文档介绍：电镀废水是全球主要的重金属污染源,如不经处理就直接排放,不仅会造成受纳水体的污染,影响水资源环境,还会造成水资源和贵金属的巨大浪费。电镀废水因镀种和工艺的不同,污染物的种类亦不同,大致可分为4 类:含氰废水、含铬废水、含镍废水和含重金属的酸性废水。电镀废水的治理方式大体可分为如下四类:物理方法、化学方法、物理化学方法和生物处理方法。
本毕业论文介绍了一步法处理电镀综合废水,一步法处理电镀综合废水, 就是在含有Cu2+ 、Fe2+、Zn 2+ 、Cr6+、CN- 等污染物的废水中按顺序加入不同药剂, 使废水中有害物质沉淀下来,或被氧化分解为无害物质的过程。过程如下: 含铬废水主要以六价铬的形式存在, 向废水中加入还原剂FeS04 可使毒性较大的六价铬还原成微毒的Cr3+, 然后再投加石灰( 或碱液) 中和废水中的酸, 把pH 值调到合适的范围就可以把废水中存在的Cu2+、Fe2+ 、Zn2+ 、Fe3+ 、Cr 3+ 等离子生成沉淀除去, 最后加入适量的漂白粉与氰化物反应1 h, -转变成无害的CO2 和N2。
-、Zn2+、Cu2 +、Cr6+、Cr总等污染物的综合电镀废水, 工艺简单、易于操作、处理高效、成本低廉, 处理过程可以达到闭路循环。该处理方法适用于中小型电镀厂对综合电镀废水的处理。
关键词:综合电镀废水;一步法;Ca( OH) 2;FeCl2;闭路循环
Abstract
Electroplating wastewater is the world's leading heavy metal pollution sources, if not treated directly discharged, will not only cause pollution of the receiving water body, affecting the water resources and environment, will result in a huge waste of water and precious metals. Electroplating wastewater of plating and process different types of pollutants are also different, and can be divided into four categories: cyanide wastewater, wastewater containing chromium, nickel-containing waste water and acidic wastewater containing heavy metals. The governance of the electroplating wastewater can be roughly divided into the following four categories: physical methods, chemical methods, physical, chemical and biological treatment methods.
This thesis introduces a one-step treatment of electroplating synthetic wastewater, one-step treatment of prehensive wastewater. In the presence of Cu2+ and Fe2+, Zn2+, Cr6+, CN-pollutants in waste water by adding different agents in order. making harmful substances in the wastewater settle down, or oxidative position to harmless substances. The process is as follows: chromium-containing wastewater is mainly in the form of hexavalent chromium reducing agent the FeCl2 allows greater toxicity of hexavalent chromium reduction by adding to the waste water into a micro-poisoning of Cr3+, and then adding lime (or lye) and wastewater acid pH val