Fe3+催化过氧化钙体系降解水中三氯乙烯

摘要

采用 Fe3+催化过氧化钙(CP)处理水溶液中三氯乙烯(TCE),考察了CP和 Fe3+投加量、地下水中常见阴离子和腐殖酸对 TCE降解效果的影响.结果表明,Fe3+催化CP体系可以有效降解 TCE,但相同药剂投加量下效率低于 Fe3+催化H2O2体系.在 TCE初始摩尔浓度为0.15 mmol/L,CP和 Fe3+投加量分别为3.00、6.00 mmol/L时,180 min时 TCE去除率达到了96.1%.常见阴离子Cl -、HCO -3和SO2 -4对 TCE的降解有抑制作用,NO -3对 TCE降解几乎无影响,而腐殖酸对 TCE降解有促进作用.自由基清除实验表明 TCE降解的主导自由基为HO ·,Cl -的释放效果显示HO·的氧化作用可使降解的 TCE完全矿化.因此,Fe3+催化CP技术适用于污染场地地下水中 TCE的修复治理.%The degradation of trichloroethylene(TCE)in aqueous solution was investigated using Fe3+catalyzed calcium peroxide(CP)system.The effects of CP and Fe3+dosages,common anions and humic acid on TCE degradation were evaluated.Results showed that TCE was efficiently removed in Fe3+catalyzed CP system,but the efficiency was lower than that in Fe3+catalyzed H2O2system at the same chemical dosage.The TCE removal rate reached 96.1% in 180 min when initial TCE concentration was 0.15 mmol/L,CP dosage was 3.00 mmol/L and Fe3+dosage was 6.00 mmol/L.Cl-,HCO -3and SO2 -4 had adverse effect on TCE degradation,NO -3showed almost no influence,while humic acid had promotion to TCE degradation.HO· was confirmed to be the main species responsible for TCE degradation and the degraded TCE was mineralized completely under HO· attack from the calculation of Cl-release performance.Therefore,Fe3+catalyzed CP technology is applicable to the remediation of TCE contaminated groundwater.