摘要随着冶金、化工等产业的日益发展，环境砷污染现象愈发严重。本课题旨在考 察出经济有效的混凝剂使用混凝沉淀法来处理含砷废水。

本论文采用了铁盐混凝沉淀法对铜冶炼厂排出的含砷废水进行处理，以硫酸亚 铁与三氯化铁为混凝剂，考察了 pH 值、反应时长和铁盐投加量三种因素对处理效 果的影响，并综合最佳条件对比两种铁盐的除砷效果得到最佳处理方法。84579

实验结果表明如果采用硫酸亚铁作为混凝剂，则在 pH 值为 9、反应时长为 3 个小时以及硫酸亚铁投加量为 231。65mg/L 时表现出最佳的除砷效果，除砷率约为 75%。而采用三氯化铁作为混凝剂时，最佳的处理条件为：pH 值为 8，反应时长为4 个小时以及三氯化铁混凝沉淀的最佳工艺条件为：混凝反应 pH 值应控制在 8 左右，反应时长应在 4 小时，三氯化铁投加量为 324。31mg/L；此时除砷率可达 86。8%左右。

由以上实验结果可知，若使用硫酸亚铁作为混凝剂需要消耗更多的石灰乳液调 节至最佳 pH，这样一来处理成本就增加了并且处理效率也没有三氯化铁高。因此 从处理效率跟处理成本上来看，使用三氯化铁作为混凝剂除砷是较为理想的选择。

毕业论文关键词：含砷废水；铁盐；混凝剂；吸附

Abstract With the development of metallurgy, chemical industry, environmental arsenic pollution is becoming more serious。 This paper aims to examine a more effective use of coagulant coagulating sedimentation method to deal with high arsenic concentration wastewater。

In this thesis, the iron salt coagulating sedimentation method was used to treat the high arsenic concentration wastewater from copper smelter。 Ferrous sulfate and ferric chloride as a coagulant, effects of pH, reaction time and a long iron salts effects of three factors on treatment effect, and comprehensive comparison of the best conditions of arsenic removal effects of two iron salts to give the best treatment method。

Experimental results show that if we use ferrous sulfate as a coagulant, at pH 9, reaction time is three hours long and ferrous sulfate dosage showed the best arsenic removal 231。65mg / L, the removal of arsenic rate of about 75%。 The use of ferric chloride as a coagulant, optimum processing conditions: at pH 8, the reaction was four hours long, and the optimum conditions for the precipitation of ferric chloride coagulation: coagulation reaction p H value should be controlled at around 8, the reaction should be four hours long, ferric chloride dosage 324。31mg / L; at this point arsenic removal rate of up to 86。8%。

From the above experimental results, if we use ferrous sulfate as a coagulant need to consume more milk of lime adjusted to the optimum pH, so to handle the cost and increase the efficiency nor high ferric chloride。 Therefore, from the processing efficiency with processing costs, the use of ferric chloride as a coagulant arsenic is an ideal alternative to。

Key Words: Wastewater contain arsenic, ferric salts, Coagulant,  adsorption。

目录

第一章 绪论 1

1。1 砷污染及其危害 2

1。1。1  砷污染现状 2

1。1。2  砷的危害 3

1。1。3  砷的环境标准 5

1。2  含砷废水处理方法 5

1。2。1 物化法 5

1。2。2  生化法 8

1。3  含砷废水处理技术的发展方向