Study On Optimization Of Electro Kinetic Remediation System Of Lead Contaminated Soil

Heavy metal contamination is one of the most harmful soil contamination types.In the remediation technologies of heavy metal-contaminated soil,the electro kinetic remediation technology（EK）has received extensive attention for its many advantages,such as short remediation period,wide adaptation range and so on.But the remediation effect of heavy metal-contaminated soil will be affected by various factors,such as electrolyte,voltage gradient,remediation period,pH value of soil and so on.And heavy metal ions will be precipitated into hydroxide with OH^-that generated by electrolytic reaction happening in anode cell when they migrate towards cathode,which will bring negative influence to remediation,namely“focusing effect”.In this paper,the typical heavy metal contaminant—Pb was taken as the target contaminant to optimize the EK remediation system by studying the influence of various factors on remediation effect.In order to weaken the negative influence of“focusing effect”,a novel permeable reactive barrier was built by H-D001 resin,which was prepared by loading H⁺on sulfonic acid group of D001 as the exchangeable ion,and the remediation effect of electro kinetic-resin barrier technology（EK-RB）was determined.The results showed that taking 0.1mol/L acetic acid as electrolyte in both two electrolytic cells,setting voltage gradient as 1.0V/cm and replacing catholyte periodically would help to improve remediation effect.The removal ratio of Pb could be improved by prolonging remediation period,but the negative influence of“focusing effect”was also enhanced.The results also showed that Pb²⁺could be adsorbed by H-D001 resin before they migrated into the area easy to be precipitated.And H⁺was desorbed when high valence cation was adsorbed by H-D001 resin,which would make the pH value of soil suitable for EK remediation.Compared with EK technology,the removal ratio of Pb after5 days increased by 37.8%relatively using EK-RB technology.