Critical layer in liquid-solid system influencing the remediation of chromium using zeolite-supported sulfide nano zero-valent iron  

作　　者：Chundi Zhou Caiyun Han Nengsheng Liu 

机构地区：[1]Faculty of Material and Environment,Guangxi University for Nationalities,Nanning 530008,China [2]College of Environmental Science and Engineering,Tongji University,Shanghai 200092,China [3]Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China

出　　处：《Journal of Environmental Sciences》2024年第1期232-241,共10页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.22066013)。

摘　　要：Sulfidated nano zero-valent iron particles were immobilized on ZSM-5 zeolite(Z/S-nZⅥ)and used for hexavalent chromium(Cr(Ⅵ))remediation.The performance of Z/S-nZⅥimproved with the increase in Cr(Ⅵ)concentration(<60 mg/L),while the performance significantly decreased for a Cr(Ⅵ)concentration of more than 60 mg/L.The adsorption behavior for Cr(Ⅵ)was different from that reported in previous studies.The improved performance can be tailored for increasing efficiency of nano zero-valent iron(nZⅥ)corrosion,while the degree of corrosion of nZⅥwas affected by the concentration of the pollutant as discussed by kinetics,X-ray diffraction(XRD)and X-ray photoelectron spectrometer(XPS)analyses.The experiments for the dissolution of ferrous ions and the dosage of adsorbent demonstrated that the critical layer in the liquid-solid system changed with the increase in the concentration of Cr(Ⅵ)(Cr(Ⅵ):Z/S-nZⅥ>0.6).Moreover,the removal mechanisms of Cr(Ⅵ)were elucidated through XRD,transmission electron microscopy(TEM)and XPS techniques.This results demonstrate that the species of chromium in the critical layer changed from Cr(Ⅲ)to Cr(Ⅵ)as the concentration of chromium increased from low to high.Furthermore,the critical layer was composed of Cr(Ⅵ),Fe(Ⅱ),O and H elements.Additionally,the experiments of coexisting ions and aging time confirmed that Z/S-nZⅥpossessed high selectivity and stability to ensure efficiency and cost-effectiveness in practical applications.

关 键 词：CR(VI) Corrosion Critical layer SELECTIVITY Stability 

分 类 号：X703[环境科学与工程—环境工程]