柠檬酸钠-Fe^2+催化纳米过氧化钙修复污染地下水

Remediation of Contaminated Groundwater Using Nano-sized Calcium Peroxide Catalyzed by Sodium Citrate-Fe^2+

为了修复被三氯乙烯污染的地下水,利用化学沉淀法制备纳米过氧化钙,采用柠檬酸钠强化Fe^2+催化效果,考察柠檬酸钠与Fe^2+的配比,以及纳米过氧化钙、柠檬酸钠-Fe^2+投加量等对修复效果的影响,并分析三氯乙烯的降解路径。结果表明:在中性条件下,柠檬酸钠-Fe^2+可以有效催化纳米过氧化钙降解地下水中的三氯乙烯;体系中纳米过氧化钙、柠檬酸钠-Fe^2+的浓度以及柠檬酸钠与Fe^2+的配比对三氯乙烯的降解有显著影响,降解反应符合伪一级动力学模型;在三氯乙烯浓度为0.16 mmol/L,柠檬酸钠与Fe^2+的物质的量比为1∶1,体系中纳米过氧化钙、柠檬酸钠-Fe^2+的浓度分别为2.88、0.96 mmol/L时,反应3 h后三氯乙烯去除率可达98.0%。

To remedy the groundwater contaminated by trichloroethylene,nano-sized calcium peroxide was prepared by chemical precipitation method,and sodium citrate was used to enhance the catalytic effect of Fe^2+.The effect of the proportion of sodium citrate and Fe^2+,as well as the concentrations of nano-sized calcium peroxide and sodium citrate-Fe^2+on the remediation,was investigated,and the degradation path of trichloroethylene was analyzed.The results show that sodium citrate-Fe^2+can effectively catalyze the degradation of trichloroethylene in groundwater by nano-sized calcium peroxide under neutral condition.The concentration of nano-sized calcium peroxide and sodium citrate-Fe^2+as well as the proportion of sodium citrate and Fe 2+have significant impact on the degradation of trichloroethylene,and the degradation reaction accords with the pseudo first-order kinetic model.When the concentration of trichloroethylene is 0.16 mmol/L,the amount of substance ratio of sodium citrate to Fe^2+is 1∶1,and the concentrations of nano-sized calcium peroxide and sodium citrate-Fe^2+are 2.88 mmol/L and 0.96 mmol/L respectively,the removal rate of trichloroethylene can reach 98.0%with the reaction time of more than 3 h.