纳米零价铁铜双金属体系对土壤中四氯双酚A的降解

Degradation of tetrachlorobisphenol A in soil by nanoscale zero-valent Copper/Iron bimetallic particles

纳米零价铁及其双金属材料因比表面积大、反应活性高,已被大量应用于地下水中卤代有机污染物、无机盐和重金属的处理,而将纳米零价铁铜双金属(Cu/n ZVI)应用于四氯双酚A(TCBPA)污染土壤的修复却鲜见报道.本文以Cu/nZVI为反应材料,探究了TCBPA起始浓度,Cu/n ZVI投加量、p H、温度等因素对土壤中TCBPA降解率的影响.批实验结果表明:反应温度为25℃,经过360 min的反应后,0.30 g的Cu/n ZVI对土壤中0.8 mg·g^(-1)TCBPA的降解率可达85%以上.Cu/n ZVI对土壤中TCBPA的降解率随TCBPA初始浓度的增加而降低,随Cu/n ZVI投加量的增加而升高,随土壤初始p H的增加而降低,Cu/n ZVI对TCBPA的降解在常温条件下即可有效的进行.Cu/nZVI对TCBPA的降解遵循准一级反应动力学模型.GC-MS结果表明,Cu/n ZVI降解TCBPA是一个逐步还原脱氯的过程.

Due to its large special surface and high reactivity,nanoscale zero-valent iron and its bimetallic particles have been widely applied to remediate organic pollutants,inorganics,and heavy metals in groundwater. However,the application of Cu/n ZVI for the remediation of Tetrachlorobisphenol A（ TCBPA） contaminated soil have been rarely reported. In this paper,the influence of initial TCBPA concentration,Cu/n ZVI dosage,initial solution p H and temperature for the degradation of TCBPA by 0.5 wt% Cu/n ZVI were studied. Batch experiments showed that the reaction can be effectively carried out under ambient conditions. TCBPA（ 0.8 mg·g^-1） could be degraded within 360 min by 0.30 g Cu/n ZVI. The degradation rates decreased with the increase of initial TCBPA concentration and soil p H. Pseudo-first-order kinetics model could be used to fit the degradation of TCBPA by Cu/n ZVI. GC-MS results elucidated that the degradation of TCBPA followed a step by step dechlorination process.