盐酸羟胺强化Fe(Ⅲ)-EDDS/过硫酸盐处理水溶液中TCE

EDDS activated persulfate process enhanced by hydroxylamine hydrochloride for treatment of trichloroethylene in aqueous solution

采用盐酸羟胺(HAH)强化Fe(Ⅲ)-EDDS(乙二胺二琥珀酸)活化过硫酸盐(PS)体系降解水溶液中的三氯乙烯(TCE).结果表明,Fe(Ⅲ)-EDDS/PS体系中加入HAH能够强化TCE去除效率,TCE降解效率随PS或HAH初始浓度增大而增强,但实验条件下存在最佳投加量.当溶液初始pH值为3~7时,Fe(Ⅲ)-EDDS/PS/HAH降解TCE基本没有影响,但碱性条件会抑制TCE去除,HAH强化工艺能够有效缓解Cl-(1~100mmol/L)和低浓度HCO3-(1~10mmol/L)对TCE降解的抑制作用.与Fe(Ⅲ)-EDDS/PS相似,加入HAH后反应体系中存在SO_4^(·-)、·OH和O_2·-,但降解TCE的主导自由基由·OH转变为SO_4^(·-).

In this study,a reducing agent,hydroxylamine hydrochloride(HAH),was applied in a Fe(Ⅲ)-EDDS activated persulfate(PS)process,and the degradation performance of trichloroethylene(TCE)was investigated.The results indicated that TCE removal was significantly enhanced with the addition of HAH in the Fe(Ⅲ)-EDDS/PS process,and TCE degradation efficiency was increased with increasing PS or HAH concentration,while an optimum concentration of PS or HAH was observed under the experimental conditions.The effects of initial solution pH(from pH 3~7),Cl-(1~100mmol/L)and HCO3-(1~10mmol/L)on TCE degradation performance were negligible,whereas alkaline conditions(pH 8~11)and high HCO3-concentration(25~100mmol/L)had negative effects.The results of ROS test showed that SO4.-,.OH,and O2.-were all generated in the Fe(Ⅲ)-EDDS/PS/HAH process,and SO4.-was the dominant radical responsible for TCE degradation.