碱活化过硫酸盐在某氯代烃污染场地地下水修复中的应用

碱活化过硫酸盐适用于降解污染土壤及地下水中的氯代烃。以典型氯代烃类污染场地为研究对象,开展了碱活化过硫酸盐降解地下水中氯代烃的小试实验研究及中试规模工程应用。结果表明：污染物去除率与污染物初始浓度、氧化剂投加比相关;污染物初始浓度越高,去除率越低;氧化剂投加量越大,去除率越高,用于该场地地下水修复的最佳氧化剂投加比为1%~3%。中试药剂原位注入采用高压旋喷注射工艺,按最佳氧化剂投加比将药剂注入至污染含水层,跟踪监测结果表明：经注药修复8个月后,地下水中氯代烃污染物浓度明显下降,大部分区域的污染物浓度已达到修复目标,局部初始浓度偏高区域的污染物浓度接近修复目标。同时,对氧化剂产物残留$ {rm{S}}{{rm{O}}^{2 - }_4}$浓度进行监测发现：$ {rm{S}}{{rm{O}}^{2 - }_4}$浓度随修复后时间延长逐渐降低,通过趋势分析预测的残留$ {rm{S}}{{rm{O}}^{2 - }_4}$浓度将逐步下降直至恢复正常水平或满足相关标准。

Remediation effect of alkali-activated persulfate in groundwater of a chlorinated hydrocarbon contaminated site

Alkali-activated persulfate is suitable to treat chlorinated hydrocarbons in contaminated soil and groundwater. Taking the typical chlorinated hydrocarbon contaminated site as the research object, the batch experiment and pilot engineering application have been conducted to degrade chlorinated hydrocarbons by alkali-activated persulfate oxidation. The experimental results showed that the pollutant removal efficiency was related to the initial concentration of pollutants and the addition ratio of oxidant. The higher the initial concentration of pollutants, the lower the removal efficiency. The larger the amount of oxidant within a certain range, the higher the removal efficiency. The optimal oxidant addition ratio was 1%~3% to treat chlorinated hydrocarbons in groundwater of the typical site. In the pilot experiment, the high-pressure rotary spray process was used to inject the oxidant with the optimal dosing ratio into the contaminated aquifer. The tracking monitoring results showed that the concentration of pollutants in the groundwater decreased significantly after 8 months remediation with the injected oxidant, the concentration of pollutants at most zones reached the remediation target, the other region with high initial concentration approached the remediation target. The concentration of oxidant-residual sulfate was monitored simultaneously, and the sulfate concentration gradually decreased with time extension. The trend analysis predicts that the concentration of residual sulfate will gradually decrease and return to a normal level or meet the relevant standards.