Efficient remediation of different concentrations of Cr-contaminated soils by nano zero-valent iron modified with carboxymethyl cellulose and biochar  

作　　者：Lihong Xie Qiyan Ma Qingjun Chen Yiyang Liu Pengfei Guo Jinlan Zhang Guilan Duan Aijun Lin Tingting Zhang Shangyi Li 

机构地区：[1]Department of Environmental Science and Engineering,College of Chemical Engineering,Beijing University of Chemical Technology,Beijing 100029,China [2]China National Petroleum and Chemical Planning Institute,Beijing 100013,China [3]State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China

出　　处：《Journal of Environmental Sciences》2025年第1期474-486,共13页环境科学学报(英文版)

基　　金：supported by the National Key Research and Development Program of China(No.2020YFC1808701);the Fundamental Research Funds for the Central Universities(No.buctrc202232).

摘　　要：Nano zero-valent iron(nZVI)is widely used in soil remediation due to its high reactivity.However,the easy agglomeration,poor antioxidant ability and passivation layer of Fe-Cr coprecipitates of nZVI have limited its application scale in Cr-contaminated soil remediation,especially in high concentration of Cr-contaminated soil.Herein,we found that the carboxymethyl cellulose on nZVI particles could increase the zeta potential value of soil and change the phase of nZVI.Along with the presence of biochar,97.0%and 96.6%Cr immobilization efficiency through CMC-nZVI/BC were respectively achieved in high and low concentrations of Cr-contaminated soils after 90-days remediation.In addition,the immobilization efficiency of Cr(VI)only decreased by 5.1%through CMC-nZVI/BC treatment after 10 weeks aging in air,attributing to the strong antioxidation ability.As for the surrounding Crcontaminated groundwater,the Cr(VI)removal capacity of CMC-nZVI/BC was evaluated under different reaction conditions through column experiments and COMSOL Multiphysics.CMC-nZVI/BC could efficiently remove 85%of Cr(VI)in about 400 hr when the initial Cr(VI)concentration was 40 mg/L and the flow rate was 0.5 mL/min.This study demonstrates that uniformly dispersed CMC-nZVI/BC has an excellent remediation effect on different concentrations of Cr-contaminated soils.

关 键 词：Carboxymethyl cellulose Nanoscale zero-valent iron BIOCHAR Cr-contaminated soils 

分 类 号：X53[环境科学与工程—环境工程]