Heavy metal removal from aqueous solutions by chitosan-based magnetic composite flocculants  

作　　者：Xuefeng Xiao Yuanyuan Yu Yongjun Sun Xing Zheng Aowen Chen 

机构地区：[1]College of Urban Construction,Nanjing Tech University,Nanjing 211800,China [2]Department of Civil and Environmental Engineering,The Hong Kong University of Science and Technology,Hong Kong 999077,China

出　　处：《Journal of Environmental Sciences》2021年第10期22-32,共11页环境科学学报（英文版）

基　　金：supported by the Natural Science Foundation of Jiangsu Province in China(No.BK20201362);2018 Six Talent Peaks Project of Jiangsu Province(No.JNHB-038)。

摘　　要：In this study,three magnetic flocculants with different chelating groups,namely,carboxymethyl chitosan-modified Fe_(3)O_(4)flocculant(MC),acrylamide-grafted magnetic carboxymethyl chitosan flocculant(MCM),and 2-acrylamide-2-methylpropanesulfonic acid copolyacrylamide-grafted magnetic carboxymethyl chitosan flocculant(MCAA)were prepared,synthesized,and characterized by photopolymerization technology.They were applied to the flocculation removal of Cr(Ⅲ),Co(Ⅱ),and Pb(Ⅱ).The effect of flocculation condition on the removal performance of Cr(Ⅲ),Co(Ⅱ),and Pb(Ⅱ)was studied.Characterization results show that the three magnetic carboxymethyl chitosan-based flocculants have been successfully prepared with good magnetic induction properties.Flocculation results show that the removal rates of MC,MCM,and MCAA on Cr(Ⅲ)are 51.79%,82.33%,and 91.42%,respectively,under the conditions of 80 mg/L flocculant,pH value of 6,reaction time of 1.5 hr,G value of 200 s^(-1),and precipitation magnetic field strength of 120 mT.The removal rates of Co(Ⅱ)by MC,MCM,and MCAA are 54.33%,84.99%,and 90.49%,respectively.The removal rates of Pb(Ⅱ)by MC,MCM,and MCAA are 61.54%,91.32%,and 95.74%,respectively.MCAA shows good flocculation performance in composite heavy metal-simulated wastewater.The magnetic carboxymethyl chitosan-based flocculant shows excellent flocculation performance in removing soluble heavy metals.This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove heavy metals in wastewater.

关 键 词：FLOCCULANT Carboxymethyl chitosan Magnetic flocculants Heavy metal FLOCCULATION 

分 类 号：TQ085.412[化学工程] X703[环境科学与工程—环境工程]