表面活性剂添加对土壤低温热脱附修复效果的影响

Effect of Surfactant Addition on Soil Thermal Desorption at Low Temperature

热脱附技术是将土壤升至一定温度,使得土壤中的有机物受热挥发而被去除,但是土壤中有机污染物通常需要较高的温度,因此修复能耗较高。本研究以乙苯和对硝基苯酚为研究对象,在小于100℃的低温脱附条件下,采用CTAB、Trition-X-100和6501为添加试剂,研究利用共沸共溶原理去除土壤中乙苯和对硝基苯酚的效果。结果表明:单一共沸处理能有效加快土壤中乙苯的去除,在1.5 h内的去除率最高可达92.5%,而添加表面活性剂后,乙苯去除的速率明显加快,反应1.5 h内乙苯去除率高达99.99%。但是,在低温条件下,添加表面活性剂于对硝基苯酚的去除并没有较大影响,最高去除仅为20%,因而利用共沸共溶原理去除土壤中的半挥发性有机物的可行性,尚待进一步研究论证。

Thermal desorption technology is to raise the soil to a certain temperature,so that the organic matter in the soil is volatilized by heat and removed,but the organic pollutants in the soil usually need a higher temperature,so the repair energy consumption is high.In this study,the removal effect of ethylbenzene and p-nitrophenol from soil by azeotrope solution principle was studied by using CTAB,Trition-X-100 and 6501 as added reagents under the condition of desorption at low temperature less than 100℃.The results showed that the single azeotrope treatment could effectively accelerate the removal rate of ethylbenzene in soil,and the removal rate was up to 92.5%within 1.5 h.However,the removal rate of ethylbenzene was significantly accelerated after the addition of surfactant,and the removal rate of ethylbenzene was up to 99.99%within 1.5 h.However,at low temperature,the addition of surfactant has no great effect on the removal of p-nitrophenol,and the maximum removal is only 20%.Therefore,the feasibility of using azeotrope solution principle to remove semi-volatile organic compounds in soil needs to be further studied and demonstrated.