A highly porous animal bone-derived char with a superiority of promoting nZVI for Cr(Ⅵ)sequestration in agricultural soils

• 作者: Kai Liu Fangbai Li Qingwen Tian Chengrong Nie Yibing Ma Zhenlong Zhu Liping Fang Yuanying Huang Siwen Liu
• 来源期刊: 环境科学学报（英文版）
• 年，卷（期）: 2021,（6）
• 页码范围: 27-39
• 页数: 13页
• 语种: 英文

摘要

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(nZVI)and apply it to remediate Cr(Ⅵ)pollution in water and paddy soil under anaerobic conditions.The batch experiments reveal that BC/nZVI ex-hibits a higher removal capacity of 516.7 mg/(g·nZVI)for Cr(Ⅵ)than nZVI when normalized to the actual nZVI content,which is 2.8 times that of nZVI;moreover,the highest nZVI uti-lization is the nZVI loading of 15％(BC/nZVI15).The Cr(Ⅵ)removal efficiency of BC/nZVI15 decreases with increasing pH(4-10).Coexisting ions(phosphate and carbonate)and humic acid can inhibit the removal of Cr(Ⅵ)with BC/nZVI15.Additionally,BC exhibits a strong ad-vantage in promoting Cr(Ⅵ)removal by nZVI compared to the widely used biochar and acti-vated carbon.Our results demonstrate that reduction and coprecipitation are the dominant Cr(Ⅵ)removal mechanisms.Furthermore,BC/nZVI15 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 nZVI.These findings provide a new effective material for remediating Cr(Ⅵ)pollution from water and soil.