Technical Note: Hydraulic Property Determination of Denitrifying Bioreactor Fill Media
Abstract
Denitrification bioreactors are one of the newest options for nitrate removal in agricultural drainage waters. Optimization of denitrification bioreactor design requires the ability to identify concrete values for the hydraulic properties of bioreactor fill media. Hydraulic properties, chiefly saturated hydraulic conductivity but also porosity and particle size, are not known for many types of possible bioreactor media though they have a significant impact upon bioreactor design and performance. This work was undertaken to more fully quantify the hydraulic properties of the major type of fill media used in Iowa denitrification bioreactors through a series of porosity, hydraulic conductivity, and particle size analysis tests. In addition, a particle size analysis was performed for two types of woodchips and one type of wood shreds in order to quantify and highlight the differences between what is commonly referred to as wood fill. Saturated hydraulic conductivity was determined for blends of woodchips, corn cobs, and pea gravel. For one of the most common types of woodchips used in bioreactors, the porosity varied from 66% to 78% depending on packing density and the average saturated hydraulic conductivity was 9.5 cm/s. It was found that additions of pea gravel significantly increased the hydraulic conductivity of woodchips though additions of corn cobs did not. Regardless of the fill mixture used, it is vital to design the bioreactor using the hydraulic properties for that specific media.
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The WB filler has the lowest possible porosity (~60 vol.%) compared to WS (~78 vol.%) and HS (~77 vol.%) fillers.
“the WB filler has the lowest possible porosity (~60 vol.% [37]) compared to WS (~78 vol.% [38]) and HS (~77 vol.% [39]) fillers”
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- Authors
- Christianson, L., Castelló, A., Christianson, R., Helmers, M., & Bhandari, A.
- Affiliations
- Iowa State University (US)
- Universitat de Lleida (ES)
- Kansas State University (US)
- Venue
- Applied Engineering in Agriculture
- Published
- 2010
- Volume
- 26
- Issue
- 5
- Pages
- 849-854
- ISSN
- 0883-8542 (ISSN-L)
- 1943-7838
- OpenAlex
- W2066537229
- Cited by
- 72
- References
- 20
- Citations by year
- 2026: 1 · 2025: 2 · 2024: 3 · 2023: 3 · 2022: 3 · 2021: 11 · 2020: 10 · 2019: 7 · 2018: 5 · 2017: 1 · 2016: 3 · 2015: 1 · 2014: 5 · 2013: 6 · 2012: 5
- FWCI
- 4.55
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Applied Engineering in Agriculture (publishedVersion)
- Iowa State University Digital Repository (Iowa State University) (submittedVersion)
- Funders
- U.S. Environmental Protection Agency
- Iowa State University
- Division of Materials Research
- Topics
- Physical Sciences › Environmental Science › Environmental Chemistry › Soil and Water Nutrient Dynamics
- Physical Sciences › Engineering › Civil and Structural Engineering › Soil and Unsaturated Flow
- Physical Sciences › Environmental Science › Environmental Engineering › Urban Stormwater Management Solutions
- Keywords
- denitrification bioreactors, saturated hydraulic conductivity, porosity, particle size distribution, wood chips, corn cob, pea gravel, agricultural drainage water, nitrate removal, bioreactor design
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