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Pig carcass-derived biochar caused contradictory effects on arsenic mobilization in a contaminated paddy soil under fluctuating controlled redox conditions
- Source :
- Journal of hazardous materials. 421
- Publication Year :
- 2021
-
Abstract
- Contamination of paddy soils by arsenic (As) is of great concern for human health and the environment. The impact of animal-derived biochar on As mobilization under fluctuating redox conditions in paddy soils has not been studied. Consequently, we investigated the effects of pig carcass-derived biochar (PB) on As (im)mobilization in a contaminated paddy soil under controlled redox potential (Eh) using a biogeochemical microcosm-setup. The addition of PB decreased the concentration of dissolved As at Eh = +100 and +200 mV by 38.7% and 35.4%, respectively (compared to the control), because of the co-precipitation of As with Fe-Mn oxides and the complexation between As and aromatic organic molecules. However, under reducing conditions (Eh = -300 mV), PB increased the dissolved As by 13.5% through promoting reduction and decomposition of As-bearing Fe minerals (e.g., ferrihydrite-As, Fe-humic-As). Under oxidizing conditions (Eh = +250 mV), PB increased the dissolved As by 317.6%, due to the associated increase of pH. We conclude that As mobilization in PB-treated paddy soils is highly affected by Eh. PB can be used to reduce the environmental risk of As under moderately reducing conditions, but it may increase the risk under highly reducing and oxidizing conditions in paddy soils.
- Subjects :
- Biogeochemical cycle
Environmental Engineering
Mobilization
Swine
Health, Toxicology and Mutagenesis
chemistry.chemical_element
Oryza
Contamination
Pollution
Decomposition
Redox
Arsenic
Soil
chemistry
Environmental chemistry
Charcoal
Oxidizing agent
Biochar
Environmental Chemistry
Animals
Soil Pollutants
Waste Management and Disposal
Oxidation-Reduction
Subjects
Details
- ISSN :
- 18733336
- Volume :
- 421
- Database :
- OpenAIRE
- Journal :
- Journal of hazardous materials
- Accession number :
- edsair.doi.dedup.....963873aff3346fed91ab2e7eec4c976b