《零价铁金属还原降解氯代有机物研究》-毕业论文.doc

兰州交通大学毕业论文 PAGE PAGE 3 精品 摘 要 有机氯化物是地下水中最常检出的有机污染物之一，它们是一种毒性强、难生物降解的环境污染物，传统的处理技术存在着降解不完全、去除率低等不足。近年来随着零价铁还原脱氯技术的迅速发展，镍/铁双金属也逐渐成为一个活跃的研究领域。本文利用单一影响因素的研究方法，以氯苯和三氯乙烯为目标污染物，研究了它们分别在单一铁和镍/铁双金属体系下，反应物初始浓度、振荡时间、铁粉投加量和初始PH值对还原脱氯速率的影响。 实验结果表明：①在单一铁体系下，氯苯在铁粉投加量较大（本次实验的最大投加量为5 g）、振荡时间t=48 h、反应物初始pH=4～5、目标污染物初始浓度较低（50 mg/L）时的降解率最高。在镍/铁双金属体系下，氯苯在铁粉量为6 g、振荡时间t=48 h、初始溶液显弱碱性、目标污染物初始浓度较低时的降解率最高；②在单一铁体系下，三氯乙烯在铁粉投加量较大（本次实验的最大投加量为5 g）、振荡时间t=48 h、反应物初始pH=4～5、目标污染物初始浓度较低（100 mg/L）时的降解率最高。在镍/铁双金属体系下，三氯乙烯在铁粉量为6 g、振荡时间t=24 h、初始溶液显弱碱性、目标污染物初始浓度较低时的降解率最高；③在镍/铁双金属体系下，氯苯和三氯乙烯还原脱氯的效果远远高于单一铁体系；④三氯乙烯的还原脱氯远比氯苯要容易得多（氯代烯烃要比氯代芳香烃容易脱氯）。 关键词：零价铁；还原脱氯； 氯苯； 三氯乙烯 ABSTRACT Chlorinated organic contaminants are commonly detected in groundwaters, they are environmental contaminants which are of strong toxicity and difficult to be biodegraded. Traditional technologies encounter some obstacles such as non-complete degradation ,remove them are not time and cost effective and so on .With an improvement of zero-valent iron reduction technology ,Ni/Fe bimetallic have become active research tocips in the last two decades. In this paper, the factors influencing the removal of chlorobenzene and trichloroethene by zero-valent iron and Ni/Fe bimetallic have been studied by experiments. Starting point concentration, oscillation time, iron powder quantity and pH initial value reacted with the rate of dechlorination. The results showed that ① when iron powder quantity is 5g ,oscillation time is 48 h, pH initial value is 4 to 5, and starting point concentration is smaller（50 mg/L）, the degradation rate of contaminants will largest if chlorobenzene have been studied by zero-valent iron. Chlorobenzene have been studied by Ni/Fe bimetallic metal when iron powder quantity is 6 g, oscillation time is 48 h ,pH initial value is weakly alkaline and starting point concentration is smaller, the degradation rate of contaminants will largest；②When iron powder quantity is 5 g ,oscillation time is 48 h ,pH initial value is 4 to