水处理渣回用修复多金属污染土壤的研究

Study on Remediation of Polymetallic Contaminated Soil by Reuse of Water Treatment Residue

研究了铁矾水处理残渣(FARS)对多金属污染土壤的修复作用。金属分馏结果表明,土壤经FARS处理后,砷(As)、铅(Pb)、镍(Ni)、锌(Zn)和铜(Cu)能以较稳定的形式转化,即As以晶态Fe/Al氧化物结合,其他金属以可氧化和残留形式存在。但铬(Cr)和镉(Cd)的形态未受影响。由于FARS的影响,钡(Ba)主要转变为更具流动性的形式。生物可及性提取试验表明,FARS使As的生物可及性降低了25%,其次是Cu、Cr、Zn、Ni和Pb。镉和钡的生物可获得性增加,特别是在试验结束时,钡的生物可及性增加了41%。总之,FARS可以用于修复受多种金属污染的土壤,但在实际应用之前,还需要进行全面的研究。

The remediation effect of jarosite water treatment residue(FARS)on polymetallic contaminated soil was studied.The results of metal fractionation show that arsenic(As),lead(Pb),nickel(Ni),zinc(Zn)and copper(Cu)can be transformed in a relatively stable form after Fars treatment,that is,as is combined with crystalline Fe/Al oxide,and other metals exist in oxidizable and residual forms.However,the morphology of chromium(Cr)and cadmium(Cd)was not affected.Due to the influence of FARS,barium(Ba)is mainly transformed into a more fluid form.The bioavailability extraction test showed that FARS reduced the bioavailability of as by 25%,followed by Cu,Cr,Zn,Ni and Pb.The bioavailability of cadmium and barium increased,especially at the end of the test,the bioavailability of barium increased by 41%.In a word,FARS can be used to repair soil polluted by various metals,but comprehensive research is needed before practical application.