Paddy soil and irrigation water are commonly contaminated with hexavalent chromium[Cr(Ⅵ)]near urban industrial areas,thereby threatening the safety of agricultural products and human health.In this study,we develop a...Paddy soil and irrigation water are commonly contaminated with hexavalent chromium[Cr(Ⅵ)]near urban industrial areas,thereby threatening the safety of agricultural products and human health.In this study,we develop a porous and high specific area bone char(BC)to support nanoscale zero-valent iron(n ZVI)and apply it to remediate Cr(Ⅵ)pollution in water and paddy soil under anaerobic conditions.The batch experiments reveal that BC/n ZVI exhibits a higher removal capacity of 516.7 mg/(g·n ZVI)for Cr(Ⅵ)than n ZVI when normalized to the actual n ZVI content,which is 2.8 times that of n ZVI;moreover,the highest n ZVI utilization is the n ZVI loading of 15%(BC/n ZVI15).The Cr(Ⅵ)removal efficiency of BC/n ZVI15 decreases with increasing p H(4–10).Coexisting ions(phosphate and carbonate)and humic acid can inhibit the removal of Cr(Ⅵ)with BC/n ZVI15.Additionally,BC exhibits a strong advantage in promoting Cr(Ⅵ)removal by n ZVI compared to the widely used biochar and activated carbon.Our results demonstrate that reduction and coprecipitation are the dominant Cr(Ⅵ)removal mechanisms.Furthermore,BC/n ZVI15 shows a significantly higher reduction and removal efficiency as well as a strong anti-interference ability for Cr(Ⅵ)in paddy soil,as compared to n ZVI.These findings provide a new effective material for remediating Cr(Ⅵ)pollution from water and soil.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21876161,42077301,41420104007)the National Key Research and Development Project of China(No.2018YFF0213403)+1 种基金the Guangdong Academy of Sciences'Project(Nos.2019GDASYL-0102006,2019GDASYL-0301002,2018GDASCX-0501)the Research Fund of China Geological Survey(DD20190703)。
文摘Paddy soil and irrigation water are commonly contaminated with hexavalent chromium[Cr(Ⅵ)]near urban industrial areas,thereby threatening the safety of agricultural products and human health.In this study,we develop a porous and high specific area bone char(BC)to support nanoscale zero-valent iron(n ZVI)and apply it to remediate Cr(Ⅵ)pollution in water and paddy soil under anaerobic conditions.The batch experiments reveal that BC/n ZVI exhibits a higher removal capacity of 516.7 mg/(g·n ZVI)for Cr(Ⅵ)than n ZVI when normalized to the actual n ZVI content,which is 2.8 times that of n ZVI;moreover,the highest n ZVI utilization is the n ZVI loading of 15%(BC/n ZVI15).The Cr(Ⅵ)removal efficiency of BC/n ZVI15 decreases with increasing p H(4–10).Coexisting ions(phosphate and carbonate)and humic acid can inhibit the removal of Cr(Ⅵ)with BC/n ZVI15.Additionally,BC exhibits a strong advantage in promoting Cr(Ⅵ)removal by n ZVI compared to the widely used biochar and activated carbon.Our results demonstrate that reduction and coprecipitation are the dominant Cr(Ⅵ)removal mechanisms.Furthermore,BC/n ZVI15 shows a significantly higher reduction and removal efficiency as well as a strong anti-interference ability for Cr(Ⅵ)in paddy soil,as compared to n ZVI.These findings provide a new effective material for remediating Cr(Ⅵ)pollution from water and soil.
