零价铁去除水中Ni2+及对有机氯脱氯的催化作用

摘要

为考察零价铁(Fe0)修复Ni2+污染水体的效果及同步修复Ni2+和有机氯的可能性,考察了Fe0对水中Ni2+的去除效果及Ni2+对有机氯脱氯的催化作用.实验结果表明,Fe0除镍反应符合拟一级反应动力学特征,表现反应速率常数(kobs)随铁粉颗粒粒径的减小而增大,铁粉颗粒粒径由2.000～0.425,0.425～0.150,0.150～0.075减小到＜0.075mm时,kobs值相应由0.022 3,0.053 8,0.104 8增加到0.1550 min-1；在考察的pH范围(2.5～10.0)内,零价铁对Ni2+保持着较高的反应速率,在酸性条件下,反应速率随着pH值的升高而降低.Fe0同步修复Ni2+和含氯有机物时,含氯有机物的存在并没有对Ni2+的去除产生很大影响,但镍的存在对Fe0脱氯具有较好的催化作用.同时,在考察的280 h内铁粉填充柱对水中的Ni2+保持着较高的去除效率(＞80％),这为Fe0修复技术的实际应用奠定了基础.%The wastewater which contain bivalent nickel (Ni2+ ) and chlorophenol or Ni2+ only are treated by zero-valent iron (Fe0) system to investigate the feasibility of using Fe0 for the remediation of Ni2+ contaminated water, or to investigate the catalysis of Ni2- for the dechlorination of chlorophenol from contaminated water by Fe0 The experimental results indicate that the reduction of Ni2+ by Fe0is pseudo-first order reaction. Superficial reaction rate constant kobs increased with the decreasing of Fe0filings' particle size. With the Fe0filings' particle size decreasing from 2.000-0.425, 0.425~0.150, 0.150~0.075 to <0. 075 mm, the koh, increases from 0.022 3, 0.053 8, 0. 104 8 to 0. 155 0 min-1 , respectively. No matter in acidity or alkalinity conditions, Fe0remains the high reactivity, and kobs, derceases with the increasing of initial pH value in acidity. When synchronous treatment of Ni2+ and 2-Chlo-rophenol, nickel has a prominent catalysis effect on the dechloridation by Fe0 , but 2-Chlorophenol has no obvious effect on the removal of Ni2+. Column filled with Fe0 powder has long distinctive removal efficiency on Ni2+ (more than 80%) in our investigating time (280 h), which indicate the feasibility of using Fe0 for the remediation of contaminated water.