零价铁
生物炭
环境修复
生物利用度
化学
土壤水分
环境化学
砷
溶解
土壤污染
降水
土壤修复
污染
土壤科学
吸附
环境科学
生态学
物理
有机化学
气象学
物理化学
生物
生物信息学
热解
作者
Pengyu Zhang,Jiangbo Fan,Xiaoyun Xu,Zibo Xu,Yulu Yu,Ling Zhao,Hao Qiu,Xinde Cao
标识
DOI:10.1016/j.jhazmat.2021.128123
摘要
Zero-valent iron-embedded biochar (ZVI/BC) is considered as an effective material for arsenic (As) immobilization in soil, but the stability of As after remediation against aging remains unknown. Herein, the effects of dry-wet and freeze-thaw aging on the immobilization of As in two As-contaminated soils amended by ZVI/BC were evaluated. ZVI/BC showed high immobilization capacity for As-contaminated soils with an over 82% decrease of bioavailable As, mainly due to the As-Fe co-precipitation accompanied with ZVI oxidation. The aging of dry-wet and freeze-thaw had an opposite effect on the bioavailability of As. After 35 rounds of dry-wet aging, bioavailable As concentration increased from 1.25-9.50 to 1.83-21.75 mg/kg, because of the oxidation dissolution of ZVI and the formation of mobile reduced As(III). By contrast, the crystallization of amorphous iron with the structural incorporation of sorbed As and the oxidation of As(III) into stable As(V) occurred during the 35 rounds of freeze-thaw aging, leading to the decrease of bioavailable As concentration from 9.50-1.25 to 5.42-0.45 mg/kg. Our results revealed that the stability of soil As after remediation by ZVI/BC varied with the different aging process, which needs more consideration for the long-term soil As immobilization in the different whether areas.
科研通智能强力驱动
Strongly Powered by AbleSci AI