淋洗-氧化顺序协同技术修复重金属及多环芳烃复合污染土壤研究OA

To study the remediation effect of the sequential combined technology of leaching and oxidation on the composite pollution of heavy metals(HMs)and polycyclic aromatic hydrocarbons(PAHs)in soil,a systematic remediation study is conducted on the soil of a nickel(Ni),antimony(Sb),benzo[a]pyrene(BaP),and dibenz[a,h]anthracene(DahA)composite pollution site in Shanghai City by using the method of experiments combined with engineering application.The results show that under the conditions of leaching time of 2 h and water-to-soil mass ratio of 5∶1,the removal effect of Ni and Sb in the soil increased with the increase of EDTA concentration.Under the conditions of maintenance time of 5 d,moisture content of 35%,and calcium oxide addition amount of 1%of soil mass,the removal effect of BaP and DahA in the soil increased with the increase of persulfate sodium addition amount.Under these conditions,in the leaching stage and oxidation stage of the contaminated soil site,0.02 mol/L EDTA and 1%(soil mass)persulfate sodium are used,respectively,and after sequential remediation by leaching and oxidation,the residual contents of Ni,Sb,BaP,and DahA in the soil are all lower than the remediation target values.The cost of remediation agents is 160.06 yuan/t,which had environmental,social and economic benefits.