硫化亚铁去除水中TCE的机理研究

Removal Mechanism of Trichloroethylene from Water by Iron Sulfide

[目的]以地下水中常见氯代烃污染物三氯乙烯(TCE)为目标污染物,采用自制硫化亚铁(Fe S)作还原剂,探讨两种物质的反应情况。[方法]在厌氧环境下,通过批试验方法研究不同影响因素下硫化亚铁降解TCE的反应动力学并探讨反应机理。[结果]在50℃下,污染物初始浓度为20 mg/L,硫化亚铁浓度为10 g/L,反应48 h后,TCE的去除率可达到80%。硫化亚铁降解TCE的反应符合伪一级动力学反应,反应速率常数(K)为0.032 8 h-1,半衰期为21.13 h。对比试验结果显示,12 h后硫化亚铁吸附TCE达到吸附/解吸平衡,之后TCE的去除以化学降解为主。[结论]硫化亚铁对TCE有一定的降解和吸附作用,反应的主要产物为乙炔。

[Objective] The most widely existent pollutant trichloroethylene （TCE） was chosen as the target pollutant,and the self-made iron sulfide （FeS） was chosen as reductant to investigate the removal ability of chlorinated hydrocarbons.[Method] The batch experiment was used to investigate the reaction kinetics,influencing factors and dechlorination mechanism of TCE in anaerobic environment.[Result] The experimental results show that when the iron sulfide initial concentration is 10 g/L and the initial concentration of pollutant is 20 mg/L,removal efficiency of TCE reaches 80％ at 50 ℃ within 48 h.The removal of TCE by iron sulfide follows the pseudo-first order reaction kinetics.Reaction rate constant （K） is 0.032 8 h-1 and half time （t1/2） is 21.13 h.The results of comparison experiment show that the adsorption of TCE on iron sulfide reached adsorption-desorption equilibrium within 12 h,then the removal of TCE primarily by chemical degradation.[Conclusion] Trichloroethylene can be degraded and absorbed by iron sulfide,and the main reaction product is acetylene.