有机污染场地氧化剂需求量及不同活化条件下氧化剂降解动力学研究

Study on oxidant demand and degradation kinetics of oxidant under different activation conditions in organic polluted sites

本文通过试验讨论了有机物污染场地不同活化条件下氧化剂过硫酸钠的消耗量和体系pH变化情况。试验发现,采用A矿物活化和D螯合铁活化更容易使土壤恢复其原本的理化特性,并初步确定本场地土壤修复对应的氧化剂需求量为:C生石灰活化(28.02g/kg)>B常规碱活化(21.26g/kg)>D螯合铁活化(19.68g/kg)>A矿物活化(16.12g/kg);经初步分析推断,过硫酸钠氧化苯并(a)芘是动力学一级吸热反应,A矿物活化、B常规碱活化、C生石灰活化、D螯合铁(Fe(Ⅲ)-EDTA)活化过硫酸钠的降解过程均符合动力学一级反应特征。

In this paper,the consumption of the oxidant sodium persulfate and the pH change of the system under different activation conditions were discussed.It was found that mineral A activation and D chelating iron activation were more likely to restore the original physicochemical properties of the soil.The oxidant requirements for soil remediation in this site were preliminarily determined as follows:C quicklime activation(28.02g/kg)>B conventional alkali activation(21.26g/kg)>D chelating iron activation(19.68g/kg)>A mineral activation(16.12g/kg).Through preliminary analysis,it was concluded that sodium persulfate oxidized benzo(a)pyrene is a kinetic first-order endothermic reaction,and the degradation processes of a mineral activation,B conventional alkali activation,C quicklime activation,and D chelated iron(Fe(Ⅲ)-edta)activation of sodium persulfate all conform to the characteristics of the first-order reaction.