A Study On Remediation Of Cr(?)?pb(?)and Cd(?)in Groundwater By Humus-supported Nanoscale Zero-Valent Iron

Groundwater is indispensable to human life and production resources.With the rapid development of people's living standards improve and industrial,the problems of groundwater pollution have not allow to ignore,heavy metal pollution is particularly serious.Heavy metal has the characteristics of high toxicity,easy to migrate and agglomeration,difficultly degraded in the environment,which ecological environment and human health were also threatened immensely.In recent years,nanoscale zero-valent iron(NZVI)has gradually become the hot of heavy metal pollution of groundwater repair material,many scholars through a variety of experimental technology proves that nanoscale zero-valent iron in the treatment of heavy metal pollution of groundwater shows superior performance.However,because of nanometer zero-valent iron poor stability,easy reunion,this brings the new challenges to the actual site remediation.Therefore,how to overcome lack of nanometer zero-valent iron has become a research hotspot.This article use humus supported nanoscale zero-valent ioron(H-NZVI)material successfully solved the problems of easily aggregation and poor stability.Meanwhile H-NZVI was characterized by SEM,TEM,BET,XRD,Zeta and XPS,suggested that the stability of humus and nanoscale zero-valent iron was relatively stable loaded on the surface of humus soil.H-NZVI was used for remedying the groundwater environmen contaminated by Cr(?),Pb(?)and Cd(?).The research shows that the remediation of chromium,lead,cadmium influenced by pH,initial concentration of heavy metals,dosage of H-NZVI.The results show that the removal rates of Cr(?),Pb(?)are decreased with increasing pH value,initial concentration of Cr(?),Pb(?)while increased with the increasing of H-NZVI dosage;the removal efficiency of Cd(?)which increase with the increasing of pH value and H-NZVI dosage but decreased with the initial concentration of Cd(?).Co-existing ions of Mg2+ has promoting effect on the removal of Cr(?),Pb(?)and Cd(?).The heavy metals of Cr(?),Pb(?),Cd(?)in groundwater adsorption and reduction by H-NZVI,which consist with the first order kinetics equation,adsorption and chemical reduction reaction at the same time.