电絮凝法处理含重金属冶炼废水工艺研究

Research on Electro-Coagulation for the Treatment of Heavy Metal From Smelting Wastewater

铅锌冶炼工业是有色金属行业中的高污染行业,除铅锌冶炼过程中提炼得到的少量金属之外,还包括其他有色金属,一般含有铅、锌、铬、铜、砷、汞、氟、氰等。由冶炼过程决定了铅锌冶炼废水具有水量大、重金属离子种类多、水质复杂多变、酸度大、污染强度大等特点。这些成分到环境中不易降解,只能通过另外的形式停留在环境中,不但造成金属资源的浪费,同时影响生态环境和人类健康,而铅锌冶炼又是有色金属冶炼行业的重要组成部分,是污染物产生的主要源头之一,因此,对铅锌冶炼行业的污水进行治理尤为重要。目前处理重金属铅锌冶炼废水的主要方法为化学沉淀中和法,尤其以中和沉淀法应用较为普遍。但是由于中和石灰法存在着种种缺陷,如出水重金属离子浓度较高、产生渣量大、脱水困难、二次污染等缺点。正是由于这些限制因素制约了其在铅锌冶炼废水中的应用,而电絮凝法具有重金属去除率高,产生渣量少且可以回收,沉淀絮凝脱水效果好等优点弥补了石灰中和法的缺陷。本文就是基于这一思路,用石灰电絮凝耦合技术处理重金属铅锌冶炼废水,并主要针对株洲冶炼集团废水进行工艺技术改造,石灰电絮凝耦合技术在技改中得到成功应用,主要内容如下：通过石灰电絮凝法处理重金属效果和成本分析得到结论如下：石灰电絮凝法在pH=8,极板电压为2v/1.5A,极板间距为0.8cm,电解时间为40min得到最佳实验条件,具有最佳的处理效果。

Lead and zinc smelting industry is high pollution industries of non-ferrous metals industry, in addition to the lead and zinc smelting process to extract a small amount of metal, also includes other non-ferrous metal, generally contain lead, zinc, chromium, copper, arsenic, mercury, fluoride, cyanide and other. From the smelting process, it is decided that the lead and zinc smelting wastewater has the characteristics of large amount of water, many kinds of heavy metal ions, complex and changeable water quality, high acidity and high pollution intensity. These components into the environment is not easy to degrade, but can only stay in another form in the environment, not only caused waste metal resources, but also affecting the ecological environment and human health, and lead and zinc smelting is non-ferrous metal smelting industry an important part, is one of the main source of pollutant generation. Therefore, the lead and zinc smelting industry wastewater treatment is particularly important. At present, the main methods to deal with the waste water of heavy metal lead and zinc smelting are chemical precipitation neutralization method, especially in the neutralization precipitation method. However, due to the neutralization of the lime method, there are various defects, such as high concentration of heavy metal ions in water, resulting in a large amount of slag, dehydration, two pollution, etc.. It is because of these limitations restrict its application in lead and zinc smelting wastewater, and electrocoagulation with heavy metal removal rate is high and the generated slag is less and can be recycled, sedimentation flocculation and dewatering effect and good to make up for deficiencies in the lime neutralization method. This article is based on this idea, with lime electroflocculation coupling technology processing heavy metals lead and zinc smelting waste water, and mainly for the wastewater of Zhuzhou Smelter Group of technical reformation, electric lime flocculation coupling technology in the technological transformation of obtained successful application, the main contents are as follows： through limestone electric flocculation treatment of heavy metal effect and cost analysis, we come to the conclusion as follows： Lime electrocoagulation in p H, electrode voltage for 2v/1.5A, plate spacing is 0.8cm, electrolytic time is 40 min get optimum experimental conditions, with the effect of the best.