As typical persistent organic contaminants, DDTs pollution has received much attention due to their persistence and high toxicity although it has been banned for many years, so it is highly important to develop efficiently methods for DDTs remediation. In this study persulfate activated with micro/nano-Fe0 particles for DDTs degradation in soil was investigated, and the effects of micro/nano-Fe0 dosage, persulfate concentration, reaction time and combined elutes-oxidation on the removal efficiency of DDTs were also examined. The results indicated persulfate was activated efficiently with micro/nano-Fe0 for DDTs degradation in soil. With persulfate concentration of 100 mmol/L and micro/nano-Feo loading of 44.8 g/L, the degradation efficiencies of p,p'-DDT and o,p'-DDT were 92.2% and 95.1%, respectively. Combined elute-oxidation was also efficient for DDTs degradation in the elutes, and among the three surfactants including Tween80, Brij35 and SDBS, the highest degradation efficiency of DDTs was observed in Brij35 solution, which indicated that Brij35 is the best elute in the combination of elute-oxidation processes. This study provides a new method for the remediation of DDTs contaminated soil with persulfate activation technologies.%作为典型的持久性有机污染物,DDTs尽管已被禁止使用,但由于其稳定的结构,土壤中仍然残留大量的DDTs,亟需开发快速高效的DDTs降解技术.基于此,本文研究了微米尺寸具有纳米单元的铁粉(微纳铁,micro/nano-Fe0)活化过硫酸钠(sodium persulfate,PS)降解场地污染土壤中DDTs的效果,并考察了微纳铁负载量、过硫酸钠浓度、反应时问及氧化一洗脱耦合对DDTs去除效率的影响.研究结果表明:微纳铁能有效活化PS降解土壤中的DDTs,在PS浓度为100 mmol/L时,DDTs的降解率随着微纳铁负载量增加而增加,当微纳铁升高到44.8 g/L时,p,p'-DDT和o,p'-DDT的降解率高达92.2%和95.1%.洗脱一氧化耦合实验中,3种表面活性剂Tween80、Brij35和SDBS,其中Brij35土壤洗脱液中DDTs的降解效率最高,微纳铁和PS的摩尔比为4:1时,对DDTs有最佳的降解效果.以卜-研究结果为DDTs的去除提供了一种新的途径,也为其他有机污染场地的修复提供了一类新技术.
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