Remediation of heavy metal-organic compound polluted soil by calcium oxide activated persulfate oxidation
The calcium oxide activated persulfate oxidation method was studied to remediate heavy metal-organic compound polluted soil.Influence of sodium persulfate dosage,ratio of sodium persulfate to calci-um oxide,soil and water ratio on the restoration effect were investigated,and the mechanism was dis-cussed.The result showed that the dosage of sodium persulfate was 2.5 mmol/g,the dosage ratio of sodi-um persulfate and calcium oxide was 2:5,and the water-soil ratio was 3∶1,the passivation rate of mercury and arsenic were 81％and 83％,and the existing forms of mercury and arsenic were converted from weak acid extraction state to more stable residue state,and the removal rate of chloroform,benzene,total petro-leum hydrocarbons and 1,2,3-trichloropropane reached 99％,98％,82％and 80％.On one hand,calci-um oxide catalyzes persulfate to generate sulfate radicals and hydroxyl radicals to oxidize heavy metals and degrade organic substances.On the other hand,mercury and arsenic are passivated through physical seal-ing and adsorption,complexation and precipitation.The study lays a foundation to the practical application of heavy metal-organic compound contaminated soil remediation technology.
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维普
