High Temperature Co-pyrolysis Thermal Air Activation Enhances Biochar Adsorption of Herbicides from Surface Water
Abstract
Recent interest has arisen in the use of biochar as a low-cost adsorbent for control of organic micropollutants in water. However, compared with activated carbon (AC), biochar adsorption capacity is typically one to two orders of magnitude lower. This study reports batch mode adsorption of anionic (2,4-D, C 0 100 μg/L) and neutral (simazine [SZN], C 0 1.5 μg/L) herbicides from surface water containing dissolved organic matter at 4 mg/L total organic carbon concentration. Enhanced adsorption was observed by biochars generated from updraft gasifiers under conditions of simultaneous co-pyrolysis thermal air activation (CPTA). 2,4-D adsorption by ≥850°C CPTA biochars was more than 10 times greater on a mass basis compared with biochars generated from a conventional anoxic pyrolysis (CAP) reactor and was equivalent to AC reference adsorbents on a surface area normalized basis. Biochars generated at ≥850°C under CPTA conditions had similar micropore surface area to CAP biochars (∼330 m 2 /g) but about 2.5 times the mesopore surface area (∼110 m 2 /g CPTA, ∼40 m 2 /g CAP), suggestive of increased pore accessibility generated by thermochemical widening of pores and/or removal of pyrolysis tars by CPTA. 2,4-D adsorption from surface water was shown to correlate strongly with biochar H:C molar ratio within but not between biochars grouped by CAP and CPTA generation conditions. Comparing adsorption of 2,4-D and SZN by biochars generated from CAP and CPTA conditions suggested that herbic…
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Surface areas were consistent with co-pyrolysis air activation results from [120] (110 to 330 m2/g), though no air was used in our study.
“Surface areas were consistent with co-pyrolysis air activation results from [120] (110 to 330 m 2 /g), though no air was used in our study.”
Cites
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Self-citationSolar Thermal Processing to Disinfect Human Waste
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Evaluating landfill leachate treatment by organic municipal solid waste-derived biochar
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- Authors
- Kearns, J. P., Shimabuku, K. K., Knappe, D. R. U., & Summers, R. S.
- Affiliations
- North Carolina State University (US)
- University of Colorado Boulder (US)
- Corresponding author
- Kearns, Joshua P.
- Venue
- Environmental Engineering Science
- Publisher
- SAGE Publications
- Published
- 2019-06-01
- Volume
- 36
- Issue
- 6
- Pages
- 710-723
- ISSN
- 1092-8758 (ISSN-L)
- 1557-9018
- OpenAlex
- W2920825867
- Cited by
- 31
- References
- 44
- Citations by year
- 2026: 5 · 2025: 4 · 2024: 3 · 2023: 4 · 2022: 8 · 2021: 4 · 2020: 3
- FWCI
- 1.36
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Environmental Engineering Science (publishedVersion)
- Topics
- Physical Sciences › Environmental Science › Water Science and Technology › Adsorption and biosorption for pollutant removal
- Physical Sciences › Engineering › Biomedical Engineering › Environmental remediation with nanomaterials
- Physical Sciences › Environmental Science › Pollution › Pesticide and Herbicide Environmental Studies
- Keywords
- biochar, herbicide adsorption, 2,4-D, simazine, surface water, dissolved organic matter, micropollutants, pore structure, surface functional groups, hydrogen bonding, activated carbon comparison
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