The DOI matches its Crossref record; 56 of the 75 references it cites were found in a registry or an index, and 19 are not checked yet; none of the 39 sources its claims cite is checked for support yet.
A Mathematical Model for the Release, Transport, and Retention of Per‐ and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone
Open accessAbstract
Per‐ and polyfluoroalkyl substances (PFAS) are emerging contaminants of critical concern. As surfactants, PFAS tend to accumulate at air‐water interfaces and may stay in the vadose zone for long times before contaminating groundwater. Yet not well understood, the extent of retention in the vadose zone has critical implications for risk management and remediation strategies. We present the first mathematical model that accounts for surfactant‐induced flow and solid‐phase and air‐water interfacial adsorption. We apply the model to simulate PFOS (a PFAS compound of primary concern) transport in the vadose zone at a model fire‐training area site impacted by aqueous film‐forming foam (AFFF). Air‐water interfacial adsorption is shown to have a significant impact—amplified by the low water content due to gravity drainage—total retardation factors range from 233 to 1,355 for the sand and 146 to 792 for the soil used in the study. The simulations illustrate it can take several decades or longer for PFOS to reach groundwater. Counterintuitively, the lower water content in the sand—due to stronger drainage and weaker capillary retention—leads to retardation factors greater than for the soil. Also, most PFOS is adsorbed at air‐water interfaces with only 1–2% in the aqueous phase. The implications include (1) fine‐texture materials could have lower retardation factors than sand due to higher retained water content, (2) soil PFAS concentrations are likely to be orders of magnitude higher than those in groundwater at source zones. Both implications are consistent with recent field observations at hundreds of AFFF‐impacted sites.
Checked 2026-10-06 · 19 references not checked yet
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The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Counterintuitively, the lower water content in the sand—due to stronger drainage and weaker capillary retention—leads to retardation factors greater than for the soil.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Abstract
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The overall time scale for PFOS to reach groundwater has increased by one to two orders of magnitude from 1 or 2 years to several decades or longer.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Among the four scenarios, PFOS propagates the slowest with the low PFOS concentration under a semi-arid climate—the front has only migrated down 2 meters after 40 years.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For Vinton, the wetting front propagation is considerably slower—it takes ~ 60 days for the wetting front to reach the groundwater table (Fig. 4(b)).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Problem setup
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The results show that it takes ~ 5 days for the wetting front to reach the groundwater table in the Accusand (Fig. 4(a)).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Problem setup
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“total retardation factors range from 233 to 1355 for the sand and 146 to 792 for the soil used in the study.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Abstract
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The extent of retardation varies among different climates and PFOS concentrations.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“the scenarios without air-water interfacial adsorption also produce much slower PFOS migration than those in the Accusand simulations.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“the surface tension drops from 65.7mN/m to 52.8mN/m when the aqueous concentration increases from 2mg/L to 20mg/L.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“After PFOS reaches the higher water saturation zone near the groundwater table, saturation and air-water interfacial area become more sensitive to capillary pressure head.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For all cases, the total cumulative mass of PFOS increases linearly before PFOS reaches groundwater.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“When air-water interfacial adsorption is turned off, the cumulative PFOS in the vadose zone plateaus at a much higher value than that of the Accusand case.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“though Vinton has higher relative permeabilities because of the higher water content”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaindirect- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“It takes ~ 5 years (high PFOS concentration; humid climate) to ~ 20 years (low PFOS concentration; semi-arid climate) for the PFOS to reach groundwater.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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In the paper
“Our simulations show rather counterintuitively that the Vinton soil has lower PFOS retardation factors compared to the Accusand.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plaincorrelational- Asserted: passes — The authors put it forward as true.
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In the paper
“The majority of the PFOS in the vadose zone is adsorbed at air-water interfaces.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plain- Asserted: passes — The authors put it forward as true.
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The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The partitioning of mass between air-water interfacial adsorption, solid-phase adsorption, and aqueous phase varies over time, primarily driven by time-dependent rainfall events.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
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The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The remainder are adsorbed at the air-water interfaces.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plain- Asserted: passes — The authors put it forward as true.
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The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“the impact is slightly greater for Vinton soil than that for Accusand.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The PFOS moves much slower when compared to the Accusand simulations.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
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In the paper
“The retardation factors—though varying with PFOS concentrations, climates, and different types of porous media—are always on the order of several hundreds to more than one thousand.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
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In the paper
“A major difference between low and high PFOS concentrations is the value of K¯aw—it decreases by 5 to 10 times from low to high PFOS concentrations”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“After PFOS reaches groundwater, the cumulative mass plateaus with slight variations driven by seasonal and interannual variations of rainfall.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“its saturated hydraulic conductivity is much smaller (~ 18 times smaller; see Table 1).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“By applying the model to simulate PFAS (using PFOS as a representative PFAS) transport in a vadose zone beneath a synthetic FTA site, we show that adsorption at air-water interfaces has a significant impact on the transport and retention of PFAS.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
boosteddirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“PFOS-induced flow has a relatively minor impact on PFOS transport and migration in the vadose zone for both Accusand and Vinton soil, especially before PFOS reaches groundwater”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“R¯ ranges from 233 to 1355, and are mainly contributed by the air-water interfacial adsorption; it accounts for more than 97% of the retardation.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The fraction of the aqueous phase PFOS is still very small—one or two percent.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“R¯ ranges from 233 to 1355, and are mainly contributed by the air-water interfacial adsorption; it accounts for more than 97% of the retardation.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“PFOS migration is still substantially slower for the scenarios that considered the air-water interfacial adsorption compared to those with air-water interfacial adsorption turned off.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For the semi-arid case, more than 93% of the mass in the vadose zone is adsorbed at the air-water interfaces.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“the solid-phase adsorption in Vinton is much greater (with a Kf that is ~ 9 times larger than Accusand).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The water content is down to 0.037 (corresponding to a water saturation of 0.126).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“After 40 years, PFOS reaches groundwater for only the high PFOS concentration case under a humid climate.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“the time scale to reach groundwater is only ~ 5 times greater when air-water interfacial adsorption is included.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“It is larger for Vinton, which accounts for approximately 44% of the total rainfall.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The retardation factors—though vary among the different scenarios—are always on the order of several hundred to more than one thousand.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
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In the paper
“For the low PFOS concentration scenarios, surface evaporation only accounts for approximately 16% of the total rainfall in the Accusand simulations.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“For the conditions we simulate, it takes several decades or longer to reach a groundwater table at ~ 5m below the land surface.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The detailed simulations show that adsorption at air-water interfaces has a strong impact on the migration and retention of PFOS in the vadose zone.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
boosteddirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Assuming these AFFF concentrates are either 3% or 6%, it leads to a PFOS concentration from 147 mg/L to 684 mg/L after dilution.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Data and parameters
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“Here we focus on two processes—solid-phase and air-water interfacial adsorption, that are the primary processes of concern for PFOS and similar PFAS.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Mathematical models > Transport of PFAS
What the sources say
- Not checked yetcites Brusseau, 2018
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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None of the sources cited for this claim have been checked yet.
In the paper
“The prior modeling studies incorporated solid-phase adsorption for the transport of surfactants, but not fluid-fluid interfacial adsorption.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Introduction
What the sources say
- Not checked yetcites Smith & Gillham, 1994
- Not checked yetcites Henry and Smith, 2003
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“To date, all of these theoretical and experimental studies employed or assumed steady-state flow conditions. The impact of transient variably saturated flow on the transport and retention of PFAS has not been considered.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Introduction
plain- Asserted: passes — The authors put it forward as true.
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None of the sources cited for this claim have been checked yet.
In the paper
“PFOS is used as a representative PFAS because of its dominance in AFFF solutions (Houtz et al., 2013; Høisæter et al., 2019).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Introduction
What the sources say
- Not checked yetcites Houtz et al., 2013
- Not checked yetcites Høisæter et al., 2019
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Second, the solid-phase adsorption is nonlinear with an exponent N < 1 and thus the effective linear adsorption coefficient will decrease for a higher aqueous concentration.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
In the paper
“The transport and fate processes of PFAS in the vadose zone in the presence of complex fluid-fluid interfaces are not well understood (SERDP, 2017).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Introduction
What the sources say
- Not checked yetcites SERDP, 2017
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These interactive processes lead to a system where variably saturated flow and PFAS transport and adsorption are fully coupled.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Introduction
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These distributions of water saturation (or water content) and air-water interfacial area have strong implications on the transport simulations in the following two sections, namely they amplify the impact of air-water interfacial adsorption on the retention of PFOS in the vadose zone.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Problem setup
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
None of the sources cited for this claim have been checked yet.
In the paper
“A number of field studies have demonstrated that the vadose zone can serve as a source zone of PFAS (Filipovic et al., 2015; Xiao et al., 2015; Weber et al., 2017; Anderson et al., 2019; Dauchy et al., 2019; Høisæter et al., 2019).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Introduction
What the sources say
- Not checked yetcites Filipovic et al., 2015
- Not checked yetcites Xiao et al., 2015
- Not checked yetcites Weber et al., 2017
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“To the best of our knowledge, no models for PFAS transport to date have accounted for both transient variably saturated flow and solid-phase and fluid-fluid interfacial adsorption processes.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Introduction
hedged- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Eq. (11) shows that Kaw monotonically increases as C decreases and asymptotically approaches a maximum value.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Mathematical models > Transport of PFAS
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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In the paper
“Houtz et al. (2013) analyzed AFFF concentrates manufactured between 1984–2010 from various manufacturers; PFOS concentration was reported to range from 4.9–11.4 g/L.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Data and parameters
What the sources say
- Not checked yetcites Houtz et al., 2013
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Conversely—as surfactants—PFAS present in solution can modify surface tension and hence impact flow.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Introduction
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
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A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“First, the air-water interfacial adsorption coefficient becomes smaller (see Fig. 3).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
None of the sources cited for this claim have been checked yet.
In the paper
“The solid-phase adsorption Cs can be modeled by the nonlinear Freundlich isotherm as suggested by prior experimental measurements (Higgins & Luthy, 2006; Wei et al., 2017; Brusseau, Khan, et al., 2019; Brusseau, 2020)”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Mathematical models > Transport of PFAS
What the sources say
- Not checked yetcites Higgins & Luthy, 2006
- Not checked yetcites Wei et al., 2017
- Not checked yetcites Brusseau, 2020
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
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None of the sources cited for this claim have been checked yet.
In the paper
“The model for surfactant-induced flow has been validated by application to sand-packed column and flow cell experiments (Smith & Gillham, 1999; Henry & Smith, 2002; Henry et al., 2002; Karagunduz et al., 2015).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
What the sources say
- Not checked yetcites Smith & Gillham, 1999
- Not checked yetcites Henry & Smith, 2002
- Not checked yetcites Henry et al., 2002
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
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None of the sources cited for this claim have been checked yet.
In the paper
“Good agreement of breakthrough curves between simulation and experiment were reported (Brusseau, Yan, et al., 2019; Brusseau, 2020).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
What the sources say
- Not checked yetcites Brusseau, Yan, et al., 2019
- Not checked yetcites Brusseau, 2020
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“the computed water content is consistent with measured water content in large lysimeters (4 m deep and 2.5 m in diameter) packed with the Vinton soil at The University of Arizona’s Karsten Center for Turfgrass Research (Young et al., 1996; Carlson et al., 2003).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
What the sources say
- Not checked yetcites Young et al., 1996
- Not checked yetcites Carlson et al., 2003
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“The water content in the lysimeters was 528 observed to reach as low as 0.035.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
What the sources say
- Not checked yetcites Young et al., 1996
- Not checked yetcites Carlson et al., 2003
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The large contributions of air-water interfacial adsorption are caused by the low water content and the corresponding high air-water interfacial areas.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“the individual components of the formulations have been validated by prior experiments.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
What the sources say
- Not checked yetcites Smith & Gillham, 1999
- Not checked yetcites Henry & Smith, 2002
- Not checked yetcites Henry et al., 2002
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“The solid-phase and air-water interfacial adsorption formulations have been used to model PFAS transport in soil/sand-packed columns under steady-state unsaturated flow.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
What the sources say
- Not checked yetcites Brusseau, Yan, et al., 2019
- Not checked yetcites Brusseau, 2020
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This implies that the total PFAS concentration in the vadose zone is likely orders of magnitude higher than that in groundwater beneath source zones.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Laboratory-measured parameters used in the simulations are representative of field-scale vadose zone conditions.
In the paper
“We note that other partitioning processes may be relevant for some PFAS such as partitioning to the air phase and organic immiscible liquids (when present) (Brusseau, 2018). Here we focus on two processes—solid-phase and air-water interfacial adsorption”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Mathematical models > Transport of PFAS
What the sources say
- Not checked yetcites Brusseau, 2018
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“our results appear to imply that a fine-texture porous medium that can retain more water in the vadose zone, for example silt or clay, could have a lower retardation factor than sand materials similar to the scenarios of the Vinton soil vs. Accusand in the present work.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Laboratory-measured parameters used in the simulations are representative of field-scale vadose zone conditions.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The retardation factors decrease from low to high PFOS concentration scenarios, similar to Accusand, due to the reduction in the air-water interfacial adsorption coefficients caused by the increase in the aqueous PFOS concentration.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Because water content and air-water interfacial areas have a major impact on the retention of PFAS transport in the vadose zone, other factors that can influence water content and the amount of air-water interfacial area will thus also have an impact on the retention.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“the presence of PFOS surfactant—by modifying the capillary pressure head and the soil water characteristic curve—has a more noticeable impact, though still not significant, on PFOS transport.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plainconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“To the best of our knowledge, this is the first mathematical model for PFAS transport in the vadose zone that explicitly accounts for the solid-phase and air-water interfacial adsorption processes.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: unclear — It is unclear why the paper says it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The fraction of the air-water interfacial adsorption is slightly less in the high PFOS concentration scenario because of a lower Kaw.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This implies that the amount of PFOS that goes into the vadose zone is comparable to the amount that is discharged to groundwater after this point.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“soil PFAS concentrations are likely to be orders of magnitude higher than those in groundwater at source zones.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Abstract
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These errors are small enough with no impact on PFOS transport in the vadose zone”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“fine-texture materials could have lower retardation factors than sand due to higher retained water content”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Abstract
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“surfactant-induced flow will likely have a greater impact on PFOS transport in fine-texture porous media wherein the water saturation is higher”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“We expect that vadose zones with deeper groundwater 529 tables (4.82m is set in our simulations) will have similar or even lower water contents.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“Recent field investigations have shown that measured PFAS concentrations in the soil were up to six or seven orders of magnitude higher than the concentrations in the groundwater (Anderson et al., 2019; Dauchy et al., 2019).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
What the sources say
- Not checked yetcites Anderson et al., 2019
- Not checked yetcites Dauchy et al., 2019
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“We have demonstrated that such large retardation factors are mainly caused by the low water content resulting from gravity drainage.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“When large infiltration occurs due to rainfall events, the water saturation increases leading to a decrease in air-water interfacial area.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“air-water interfacial adsorption is amplified by the low water content (and hence large air-water interfacial areas) in the vadose zone caused by gravity drainage.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“This is supported by field evidence of decreasing soil to groundwater PFAS concentrations with increasing clay content.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: unclear — It is unclear why the paper says it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The lower water content caused by greater gravity drainage and weaker capillary retention in the sand has also led to a counterintuitive result that the retardation factors for the sand (233 to 1355) are larger than those for the soil (146 to 792).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“A direct implication is that fine-texture materials such as silt or clay could have lower PFAS retardation factors compared to sand due to the higher retained water content in the vadose zone.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Laboratory-measured parameters used in the simulations are representative of field-scale vadose zone conditions.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This implies that PFAS concentrations in the vadose zone are likely orders of magnitude higher than those in the groundwater in source zones”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Laboratory-measured parameters used in the simulations are representative of field-scale vadose zone conditions.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The large retardation factors lead to long time scales for PFOS to reach groundwater.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“not including the groundwater table dynamics will likely overestimate the retention of PFAS in the vadose zone.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For the high PFOS concentration scenarios, the surface evaporation is slightly lower due to more induced drainage caused by a greater reduction in surface tension.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- It may state two separate claims as one. 34
- Probably not a substantial claim. 9
- The quote only partly states this claim. 1
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For the majority of the time during the 5-day simulation, the water saturation stays below 0.25 (corresponding to a water content of 0.074) and the air-water interfacial area stays above 400 cm2/cm3 (Fig. 4(c)) despite the fact that the conditions represent the largest rainfall event.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Problem setup
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For the majority of the time, the water saturation is below 0.35 (corresponding to a water content of 0.138) and the air-water interfacial area is above 700 cm2/cm3 (Fig. 4(d)).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Problem setup
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Also, most PFOS is adsorbed at air-water interfaces with only 1–2% in the aqueous phase.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Abstract
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“A higher PFOS concentration and a more humid climate both accelerate the migration of PFOS.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Approximately 1.5% is in the aqueous phase, and the remaining 5.5% is in the solid-phase adsorption.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“the simulated water saturation above the groundwater table is generally small, and for Accusand and Vinton soil, saturation (and thus air-water interfacial area) is not sensitive to capillary pressure head (or water pressure head) at low saturations”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The other critical finding from our simulations is that the majority of the PFOS in the vadose zone is retained at the air-water interfaces—only one or two percent is in the aqueous phase.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Approximately 60% and 20% of the total released PFOS remain in the vadose zone for the semi-arid and humid climates respectively, which are almost 10 times greater than those in the Accusand scenarios.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For the humid-climate case, approximately 97% is adsorbed at the air-water interfaces, 1% is in the aqueous phase, and 2% is in the solid-phase.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“at the maximum concentration of the plume, the air-water interfacial adsorption accounts for roughly 99% and 95% of the total PFOS in the low and high PFOS concentration scenarios, respectively.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“When air-water interfacial adsorption is not considered, the total mass left in the vadose zone is substantially lower—approximately 7% and 2% remain in the vadose zone for the semi-arid and humid climates, respectively.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“When air-water interfacial adsorption is considered, approximately 58% and 45% of the total released PFOS remains in the vadose zone at 40 years, for the semi-arid and humid climates, respectively.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The solid-phase adsorption accounts for about 30% and 17% of the total mass in the vadose zone for the semi-arid and humid climates, respectively (Fig. 10), which are much higher than the corresponding Accusand values.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“a humid climate leads to a higher water content and a lower air-water interfacial area than a semi-arid climate.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds. It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The humid climate leads to higher average water content as expected.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds. The quote only partly states this claim.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The retardation factors are on the order of several hundreds—though still very large—they are lower compared to the Accusand retardation factors.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“the results show that the majority of the PFOS in the vadose zone is retained at the air-water interfaces (70% or more) and the solid surfaces (5% to 30%) leaving only one or two percent in the aqueous phase.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“The adsorption coefficients—though varying among simulations—were kept constant during each simulation, and thus have underestimated the nonlinear responses of the adsorption processes under transient flow.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Introduction
What the sources say
- Not checked yetcites Costanza-Robinson and Henry (2017)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Under a more humid climate, it is expected that PFOS will migrate faster because: 1) more water is flowing through the vadose zone to groundwater with higher pore water velocities leading to more “leaching”, and 2) the water content is likely higher leading to less air-water interfacial adsorption.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- The authors state this as an assumption: Capillary pressure head scales with surface tension according to Leverett scaling.
- The authors state this as an assumption: The contact angle does not change when PFAS is dissolved.
- The authors state this as an assumption: All precipitation is treated as rainfall, with no distinction between rain and snow.
- The authors state this as an assumption: Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
- The authors state this as an assumption: All applied AFFF solution infiltrates into the vadose zone.
None of the sources cited for this claim have been checked yet.
In the paper
“The functional relationship between air-water interfacial area and water saturation will in general depend on the drainage and imbibition history (Hassanizadeh & Gray, 1993; Reeves & Celia, 1996; Schaefer et al., 2000).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Mathematical models > Transport of PFAS
What the sources say
- Not checked yetcites Hassanizadeh & Gray, 1993
- Not checked yetcites Reeves & Celia, 1996
- Not checked yetcites Schaefer et al., 2000
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“PFAS can be released from various types of sources including fire-training area (FTA) sites, fire response sites, industrial sites, landfills, and wastewater treatment plants (ITRC, 2018).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Data and parameters
What the sources say
- Not checked yetcites ITRC, 2018
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“Høisæter et al. (2019) reported that 1:100 dilution of an AFFF concentrate leads to a PFOS concentration of 100 mg/L; PFOS is the dominant PFAS accounting for 88.7% of the total PFAS.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Data and parameters
What the sources say
- Not checked yetcites Høisæter et al., 2019
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This is rather counterintuitive because the Vinton soil has larger interfacial areas and also stronger solid-phase adsorption.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“Anderson et al. (2019) showed that the ratio between the PFAS concentration in the soil and groundwater decreases with increasing clay content, which they hypothesized is due to the higher water saturation in the presence of higher clay content.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
What the sources say
- Not checked yetcites Anderson et al., 2019
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The PFOS adsorbed at the air-water interfaces is released to the aqueous phase and the majority of that is then adsorbed to the solid surface.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“It is slightly lower for higher PFOS concentration because of possibly greater surfactant-induced drainage caused by a greater decrease of surface tension at a higher aqueous PFOS concentration.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Accusand
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“the study by Anderson et al. (2019) was based on an analysis of 324 Air Force sites across the continental US impacted by AFFF, and higher soil PFAS concentrations were observed in the vast majority (87%) of the data collected.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
What the sources say
- Not checked yetcites Anderson et al., 2019
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Hysteresis effects are not considered.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Mathematical models > Transport of PFAS
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“A 530 shallower groundwater table may increase the overall water content if the porous medium 531 has a thick capillary transition zone.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The reason is that though the Vinton soil has a larger interfacial area than the Accusand for the same water saturation, it retains much higher water saturation than the Accusand does in the vadose zone due to stronger capillary forces.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Though we have not compared our model directly to experimental data (such data does not yet exist)”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“A low water content increases the retardation factor because: 1) it is in the denominator of the expression for the retardation factor, and 2) it leads to a large interfacial area and thus more interfacial adsorption.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“To verify our implementation of the Richards’ and advection-dispersion equations, we have compared our code with HYDRUS-1D for a simulation of water infiltration and solute transport (see the supporting information (SI)). Excellent agreement between the results from the two codes is observed (Fig. S1 in the SI).”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Numerical methods
boosted- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“For all simulations performed in the present work, the relative global mass conservation error (at the end of 40 years) is less than 0.1% for water and less than 0.005% for PFOS, respectively.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“A closer inspection reveals that the Accusand has much lower water content than the Vinton soil (more than 3 times lower), which is the main reason responsible for the Accusand’s greater retardation factors.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“When looking at the contributions to the retardation factors associated with the solid-phase adsorption alone (f¯spa), they are ~ 4 times that of the Accusand f¯spa values because Vinton has a solid-phase adsorption capacity that is almost 9 times greater.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Vinton soil
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Our simulations have converged for Δx and Δt.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Results > Problem setup
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper may give no reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“the seasonal and interannual variability of the groundwater table may influence the water saturation in the vadose zone and hence the air-water interfaces, especially when the vadose zone is relatively shallow.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“not accounting for transpiration fluxes due to plant uptake will likely overestimate the water content and thus underestimate the time-scale of retention in the vadose zone.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“which is consistent with recently reported data at hundreds of AFFF-impacted FTA sites in the US and elsewhere.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Conclusion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.
In the paper
“Dauchy et al. (2019) showed that PFAS were detected 15m below ground despite the presence of clay layers implying that the retardation factors in clay may not be as great as what is usually thought for other contaminants.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Discussion
What the sources say
- Not checked yetcites Dauchy et al., 2019
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The authors state this as an assumption.
Capillary pressure head scales with surface tension according to Leverett scaling.
“Here we assume that the capillary pressure head (−h) scales with surface tension σ following Leverett et al. (1941) and Smith and Gillham (1994)”
The authors state this as an assumption.
The contact angle does not change when PFAS is dissolved.
“For simplicity, the contact angle is assumed unchanged with dissolved PFAS.”
The authors state this as an assumption.
All precipitation is treated as rainfall, with no distinction between rain and snow.
“For simplicity, we treat all precipitation as rainfall and do not distinguish between rain and snow in our simulations.”
The authors state this as an assumption.
Evapotranspiration data are approximated as potential evapotranspiration to determine surface evaporation fluxes.
“In addition, we approximate the evapotranspiration data as potential evapotranspiration to determine the surface evaporation fluxes.”
The authors state this as an assumption.
All applied AFFF solution infiltrates into the vadose zone.
“Assuming all of the AFFF solutions infiltrate into the vadose zone, it gives a total infiltration of 0.0458cm per training session.”
The paper relies on this without support.
The time scale over which PFAS may remain in the vadose zone due to fluid-fluid interfacial adsorption and the potential for long-term release to groundwater are unknown.
“In particular, the time scale that PFAS may stay in the vadose zone due to fluid-fluid interfacial adsorption and the potential long-term release to groundwater are unknown.”
The paper relies on this without support.
PFAS behave as surfactants and tend to accumulate at air-water interfaces, potentially remaining in the vadose zone for long periods.
“when released to the environment they tend to accumulate at air-water interfaces and may stay in the vadose zone for long periods of time (Fig. 1(b,c)).”
The paper relies on this without support.
The implications are consistent with recent field observations at hundreds of AFFF-impacted sites.
“Both implications are consistent with recent field observations at hundreds of AFFF-impacted sites.”
The paper relies on this without support.
Laboratory-measured parameters used in the simulations are representative of field-scale vadose zone conditions.
“though our simulations used laboratory measured parameters”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The cited source says what the claim attributes to it.
In the citing paper
“The AWI sorption capability of the extended LEACHM code has been successfully benchmarked against Guo et al. (2020) and Zeng et al. (2021”
From Model-based identification of vadose zone controls on PFAS mobility under semi-arid climate conditions (2022) · cites this paper as Guo et al. (2020)
In the citing paper
“These studies suggest that retention of PFAS in the vadose zone due to partitioning at the air–water interface and biotransformation of precursors may sustain long-term downstream contamination of the more mobile perfluoroalkyl sulfonates (PFSA) and PFCA.”
From Centurial Persistence of Forever Chemicals at Military Fire Training Sites (2023) · cites this paper as [14]
In the citing paper
“These results agree with mathematical and experimental evidence showing much larger solids retention of PFAS under unsaturated compared to saturated conditions.14,33”
From Centurial Persistence of Forever Chemicals at Military Fire Training Sites (2023) · cites this paper as [14]
In the citing paper
“Results from theoretical models and laboratory experiments in prior work suggest that PFAS retention at the air–water interface in the vadose zone is likely to be a rate-limiting step mediating attenuation at AFFF-contaminated sites.14,49”
From Centurial Persistence of Forever Chemicals at Military Fire Training Sites (2023) · cites this paper as [14]
In the citing paper
“The mathematical model that was employed to conduct the numerical simulations accounts for transient variably saturated flow, surfactant-induced flow, nonlinear and rate-limited solid-phase sorption, and nonlinear and rate-limited air-water interfacial adsorption (Guo et al., 2020).”
From PFAS concentrations in soil versus soil porewater: Mass distributions and the impact of adsorption at air-water interfaces (2022) · cites this paper as Guo et al., 2020
In the citing paper
“Guo et al. (2020) conducted long-term numerical simulations for a model fire-training source area for representative field conditions.”
From PFAS concentrations in soil versus soil porewater: Mass distributions and the impact of adsorption at air-water interfaces (2022) · cites this paper as Guo et al. (2020)
In the citing paper
“These dynamic changes of porewater concentration due to transient water infiltration are consistent with those reported in our prior work (Guo et al., 2020; Zeng et al., 2021).”
From PFAS concentrations in soil versus soil porewater: Mass distributions and the impact of adsorption at air-water interfaces (2022) · cites this paper as Guo et al., 2020
In the citing paper
“Porewater concentrations ranging up to 10’s of mg/L were obtained for PFOS, for a simulated release concentration of 1,000 mg/L.”
From PFAS concentrations in soil versus soil porewater: Mass distributions and the impact of adsorption at air-water interfaces (2022) · cites this paper as Guo et al. (2020)
In the citing paper
“PFAS in the unsaturated zone can be sources to underlying groundwater systems for decades,7,14”
From Perfluoroalkyl and Polyfluoroalkyl Substances in Groundwater Used as a Source of Drinking Water in the Eastern United States (2022) · cites this paper as [14]
In the citing paper
“The results of initial field and mathematical-modeling studies reflect these anticipated concentrations (Guo et al., 2020; Quinnan et al., 2021; Brusseau and Guo, 2022).”
From Global distributions, source-type dependencies, and concentration ranges of per- and polyfluoroalkyl substances in groundwater (2022) · cites this paper as Guo et al., 2020
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Rated minor: it would not touch a result — a value no result rests on, a p-value that stays on the same side of the significance level, or a conflict that is clerical, resolved elsewhere in the paper, or outside its own findings.
In the paper
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Abstract
“We present the first mathematical model that accounts for surfactant-induced flow and solid-phase and air-water interfacial adsorption.”
§ A Mathematical Model for the Release, Transport, and Retention of Per- and Polyfluoroalkyl Substances (PFAS) in the Vadose Zone > Introduction
“More recently, Costanza-Robinson and Henry (2017) modified HYDRUS-1D (Simunek et al., 2008) to simulate surfactant-induced flow to evaluate the aqueous air-water Interfacial Partitioning Tracer Test (IPTT) method. Both solid-phase and air-water interfacial adsorption were included.”
Citations
Cites
A Closed‐form Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils
van Genuchten, M. T. (1980) · Soil Science Society of America Journal · doi:10.2136/sssaj1980.03615995004400050002x · Cited by 27,578
Physical chemistry of surfaces
Adamson, A. W., & Gast, A. P. (1998) · Choice Reviews Online · doi:10.5860/choice.35-4499 · Cited by 11,685
A new model for predicting the hydraulic conductivity of unsaturated porous media
Mualem, Y. (1976) · Water Resources Research · doi:10.1029/wr012i003p00513 · Cited by 8,300
CAPILLARY CONDUCTION OF LIQUIDS THROUGH POROUS MEDIUMS
Richards, L. A. (1931) · Physics · doi:10.1063/1.1745010 · Cited by 6,427
Buck, R. C., Franklin, J., Berger, U., Conder, J. M., Cousins, I. T., de Voogt, P., Jensen, A. A., Kannan, K., Mabury, S. A., & van Leeuwen, S. P. (2011) · Integrated Environmental Assessment and Management · doi:10.1002/ieam.258 · Cited by 4,641
Millington, R. J., & Quirk, J. P. (1961) · Transactions of the Faraday Society · doi:10.1039/tf9615701200 · Cited by 2,273
Capillary Behavior in Porous Solids
Leverett, M. C. (1941) · Transactions of the AIME · doi:10.2118/941152-g · Cited by 2,258
A Never-Ending Story of Per- and Polyfluoroalkyl Substances (PFASs)?
Wang, Z., DeWitt, J. C., Higgins, C. P., & Cousins, I. T. (2017) · Environmental Science & Technology · doi:10.1021/acs.est.6b04806 · Cited by 1,921
A general mass‐conservative numerical solution for the unsaturated flow equation
Celia, M. A., Bouloutas, E. T., & Zarba, R. L. (1990) · Water Resources Research · doi:10.1029/wr026i007p01483 · Cited by 1,816
Sorption of Perfluorinated Surfactants on Sediments
Higgins, C. P., & Luthy, R. G. (2006) · Environmental Science & Technology · doi:10.1021/es061000n · Cited by 1,563 · cited 1×
“The solid-phase adsorption C s can be modeled by the nonlinear Freundlich isotherm as suggested by prior experimental measurements (Brusseau et al., 2019; Brusseau, 2020; Higgins & Luthy, 2006; Wei et al., 2017) 10.1029/2019WR026667 where K 𝑓 and N are fitting parameters to experimental data.”
MethodInfluential
Research works printed but not linked: 2
- 10.1021/es981355 · DOI
- Simunek J., 2008, The HYDRUS‐1D software package for simulating the one‐dimensional movement of water, Heat, and Multiple Solutes in Variably‐Saturated Media, Version, 4, 281
Cited by
Sorted by citations
PFAS concentrations in soils: Background levels versus contaminated sites
Brusseau, M. L., Anderson, R. H., & Guo, B. (2020) · Science of The Total Environment · doi:10.1016/j.scitotenv.2020.140017 · Cited by 817
Self-citationWang, D., Xiao, F., Xiao, F., Chen, J., Park, C. M., Park, C. M., Flury, M., & Flury, M. (2022) · Reviews of Geophysics · doi:10.1029/2021rg000765 · Cited by 294
Sima, M. W., & Jaffé, P. R. (2021) · Science of The Total Environment · doi:10.1016/j.scitotenv.2020.143793 · Cited by 242
McMahon, P. B., Tokranov, A. K., Bexfield, L. M., Lindsey, B. D., Johnson, T. D., Lombard, M. A., & Watson, E. (2022) · Environmental Science & Technology · doi:10.1021/acs.est.1c04795 · Cited by 183
Fate and transport of per- and polyfluoroalkyl substances (PFASs) in the vadose zone
Sharifan, H., Bagheri, M., Wang, D., Burken, J. G., Higgins, C. P., Liang, Y., Liu, J., Schaefer, C. E., & Blotevogel, J. (2021) · Science of The Total Environment · doi:10.1016/j.scitotenv.2021.145427 · Cited by 180
Metadata
- Authors
- Guo, B., Zeng, J., & Brusseau, M. L.
- Affiliations
- University of Arizona (US)
- Corresponding author
- Guo, Bo
- Venue
- Water Resources Research
- Publisher
- American Geophysical Union (AGU)
- Published
- 2020-02
- Volume
- 56
- Issue
- 2
- ISSN
- 0043-1397 (ISSN-L)
- 1944-7973
- PMC
- PMC7673302
- OpenAlex
- W2999663693
- Cited by
- 224
- References
- 74
- Citations by year
- 2026: 45 · 2025: 37 · 2024: 38 · 2023: 27 · 2022: 31 · 2021: 37 · 2020: 9
- FWCI
- 9.64
- Type
- journal article
- Language
- en
- Open access
- green
- europepmc.org
- Locations
- Water Resources Research (publishedVersion)
- PubMed (publishedVersion)
- Europe PMC (PubMed Central) (acceptedVersion)
- PubMed Central (acceptedVersion)
- UA Campus Repository (The University of Arizona) (acceptedVersion)
- Funders
- National Institute of Environmental Health Sciences (P42ES004940)
- Topics
- Physical Sciences › Environmental Science › Environmental Chemistry › Per- and polyfluoroalkyl substances research
- Physical Sciences › Environmental Science › Environmental Engineering › Groundwater flow and contamination studies
- Physical Sciences › Engineering › Civil and Structural Engineering › Soil and Unsaturated Flow
- Keywords
- per- and polyfluoroalkyl substances, PFOS, vadose zone, air-water interface adsorption, solid-phase adsorption, retention factor, groundwater contamination, aqueous film-forming foam, gravity drainage, capillary retention, source zone
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-10-06, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
A second model labelled each claim on 2026-10-06 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
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