过硫酸盐在岩溶管道地下水中的稳定性及其对苯系物的去除效果

原位化学氧化(in situ chemical oxidation,ISCO)是一种高效便捷的去除地下水有机污染物的技术,相比于多孔介质,岩溶地下河中ISCO技术应用还未见报道.为了更好地认识ISCO技术在岩溶地下河石油污染修复中应用的可行性,使用过硫酸盐(persulfate,PS)作为化学氧化剂,在实验室利用碳酸盐...

Stability of persulfate in karst conduit groundwater and its removal effect of aromatics

In situ chemical oxidation (ISCO) is an efficient and convenient technology to remove organic pollutants in groundwater. However, compared with porous media, the application of ISCO technology in karst underground rivers has not been reported yet. In order to better understand the feasibility of the application of ISCO technology in karst underground river contaminated by petroleum hydrocarbons, persulfate (PS) was used to investigate its migration ability and stability, and the effect of aromatic hydrocarbons (including benzene, toluene, ethylbenzene and xylene) removal by PS was evaluated with a carbonate conduit model in laboratory. The results showed that PS had good stability and strong migration ability in the uncontaminated karst conduit with the flow rate of 120 mL·h−1. When the concentration of injected persulfate was 21 g·L−1 and the injection flow was 15 mL·h−1, the removal rate of aromatics was 4.1 mg·h−1, and the consumption rate of PS was 86.2 mg·h−1. The removal effect of aromatics by PS in flow-water state was better than that in static-water state. The buffering of carbonate rocks could inhibit the pH decrease caused by chemical oxidation, promote carbonate karst erosion, and increase the content of calcium ion.