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Laboratory based long-term batch incubation study was carried out to assess the methane (CH4) uptake or removal capacity in the landfill cover soil, biochar-amended cover soil, and methanotrophic-activated biochar-amended cover soil. The soil was amended with biochar or activated biochar in two proportions: 2% and 10% by weight. The results indicate that the methanotrophic-activated biochar-amended soil exhibited higher CH4 uptake and oxidation rates when compared to soil and biochar-amended soil. The 10% methanotrophic-activated biochar-amended soil showed the highest CH4 uptake with the CH4 oxidation rate of 518.6 µg CH4/g/day and the landfill cover soil showed the least uptake with the CH4 oxidation rate of 88 µg CH4/g/day. Overall, this study demonstrates that the biochar activated with methanotrophs expedited the CH4 uptake process when compared to non-activated biochar-amended soil that takes longer time for microbial colonization and acclimatization. Furthermore, column studies and field scale studies under dynamic environmental conditions are being undertaken to evaluate the maximum removal of CH4 under typical landfill conditions.
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The regenerative role of biofilm in the removal of pesticides from stormwater in biochar-amended biofilters
Low-impact, green infrastructure systems such as biofilters, particularly when amended with biochar, can help address chemical pollution conveyed via stormwater that is increasingly posing a threat to aquatic ecosystems and groundwater quality. Although removal of organic contaminants including pesticides by biochar-amended systems has been studied, the role of a biofouling layer on contaminant removal, biotransformation, and filter lifetime remains poorly understood. This study evaluated the removal of the pesticides atrazine, imidacloprid, and clothianidin in biologically active biochar-amended columns through complete exhaustion of contaminant removal capacity. The resultant data indicate that biological processes accounted for 20–36% of overall removal in the biochar-amended sand columns. In addition, a combined target and suspect screening approach using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS) was employed to evaluate the potential transformation of these three pesticides and release of the transformation products (TPs). All TPs detected in the effluent remained below 2.5% of their respective parent influent concentrations for the duration of the experiment. Furthermore, at a biochar application rate of 0.5 wt%, the presence of an active biofilm prolonged the filter lifetime by 1.8–2.3 times compared to a fouled but inactive filter, where removal was presumably dominated by adsorption only. Scenario modelling estimates showed that biochar-amended biofilters could last at least 17 years before exceeding aquatic life threshold values at biochar-application rates as low as 1 wt% (5 vol%) in a representative case study. Results of this study provide novel insight on pesticide TP formation in biochar-amended biofilters and estimation of filter lifetimes.
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- Award ID(s):
- 1844720
- PAR ID:
- 10328623
- Date Published:
- Journal Name:
- Environmental Science: Water Research & Technology
- Volume:
- 8
- Issue:
- 5
- ISSN:
- 2053-1400
- Page Range / eLocation ID:
- 1092 to 1110
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d1ew00870f
