【作者】 范领东；

【导师】 徐晓军；

【作者基本信息】 昆明理工大学 ， 环境科学， 2012， 硕士

【摘要】 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,并针对蒙自矿冶有限责任公司的实际需求进行工艺技术改造,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：(1)通过石灰中和法、电絮凝法、石灰电絮凝法处理重金属效果比较和成本分析得到结论如下,石灰中和法在pH=10,搅拌反应时间为30min,搅拌强度为250r/min,并加入一定量的絮凝剂FeCl3得到最佳实验条件。电絮凝法在pH=9,极板电压为5V,极板间距为0.8cm,电解时间为40min,并进行pH=9的曝气处理得到最佳实验条件。石灰电絮凝法在pH=8,极板电压为2V,极板间距为1.2cm,电解时间为30min得到最佳实验条件。通过对这三种方法的最佳实验条件下,得到的三种方法的最佳处理效果的对比分析,得出石灰电絮凝法具有最佳的处理效果。通过对比三种方法的能耗、药品成本、设备成本,得出石灰电絮凝法具有较明显的成本优势。(2)从配位化学角度分析得到pH对Cu2+、Zn2+、Cd2+、Pb2+羟基离子形态的影响和pH值对Cu(OH)2、Zn(OH)2、Cd(OH)2、Pb(OH)2溶解度的影响。从电絮凝对重金属离子去除机理分析得到主要通过电荷中和作用、网捕作用和卷扫作用去除。并且简要分析了在极板阴极的重金属析出顺序和理论分析。(3)通过对蒙自矿冶有限责任公司的处理工艺改造,分析改造前后的出水处理效果,得到通过石灰电絮凝工艺改造后并后续加深度处理的出水能够达到地表水Ⅲ类标准,出水全部回用于生产。石灰电絮凝耦合工艺已成功应用于工程,对解决实际问题具有重要意义。总之,论文用石灰电絮凝耦合技术处理重金属铅锌冶炼废水是一种有效的处理方法并在蒙自矿冶有限责任公司技术改造上已得到成功应用,为解决冶炼废水处理提供了一种新方法、新手段和新思路。更多还原

【Abstract】 Lead and zinc smelting industry is the high-polluting industries in non-ferrous metal industry,in addition to the lead and zinc smelting process to extract a small amount of metal, also including other non-ferrous metals, generally contain lead, zinc, chromium, copper, arsenic, mercury, fluoride, cyanide and so on. From the smelting process deciding lead and zinc smelting waste water with a large amount of water, many kinds of heavy metal ions, complex and changing water quality, high acidity, and pollution intensity feature. These components into the environment is not easy degradation, but can only stay another form in the environment, not only cause metal wastage of resources,but also affecting the ecological environment and human health. Lead and zinc smelting is an important part of the non-ferrous metal smelting industry, it is a major source of pollutants therefore,to treat lead and zinc smelting industry sewage is particularly important. Currently,the main method to deal with the heavy metals lead and zinc smelting waste water is chemical precipitation, particularly the application of neutralization sedimentation method is more common.Because of the existence of various defects in lime neutralization, such as higher concentration of heavy metal ions, resulting in large amount of slag,dewatering difficulties, produce secondary pollution, and other shortcomings. It is because of these constraints restrict its application in lead and zinc smelting waste water, electricflocculation method has high removal rate of heavy metal, resulting slag is less and can be recycled, good effect of precipitation flocculation dehydration and other advantages. This article is based on this idea, with lime electroflocculation coupled technology dealing with the heavy metals lead and zinc smelting waste water, to technological innovation, for the actual needs of the process in Mengzi Mining Co., Ltd. lime electroflocculation coupling technology has been successfully applied in the technological transformation, the main content is as follows:(1) By the effect of heavy metal removal rate and cost analysis with lime neutralization,electricflocculation,lime neutralization-electricflocculation method,the conclusions are as follows:At pH is10, stirring reaction time is30min, mixing intensity for250r/min, and a certain amount of flocculant FeCl3lime neutralization method reach best experimental conditions. At pH is9, the plate voltage is5V, the plate spacing is0.8cm, the electrolysis time of40minutes, and pH=9aeration treatment, electricflocculation method reach best experimental conditions. At pH is8, the plate voltage is2V, the plate spacing is1.2cm, the electrolysis time of30min neutralization-electricflocculation reach best experimental conditions. Through the three methods under best of the experimental conditions, the comparative analysis of the three ways to get the best treatment effect to get the best treatment of three ways and then comparative analysis, obtained the lime-electroflocculation has the best treatment effect,by contrast three methods of energy consumption, drug costs, equipment costs,obtained the lime electroflocculation method has a distinct cost advantage.(2) Analysis of the coordination chemistry point of view that pH effect on Cu2+, Zn2+, Cd2+, Pb2+hydroxyl ion form and effect of pH on the solubility of Cu(OH)2, Zn(OH)2, Cd(OH)2, Pb(OH)2. Removal mechanism of heavy metal ions from the electrolyticflocculation obtained mainly by charge neutralization effect and the role of the netting effect and the volume swept effect. And a brief analysis of the precipitation sequence of the heavy metal on plate cathode and theoretical analysis.(3) Through transformation of the treatment process in Mengzi Mining Co., Ltd, analysis the treatment effect of before and after the transformation,.through the transformation by lime-electricflocculation process, and follow-up and depth of processing,water can reach the surface water III standard, All the back water for the production.Lime-electricflocculation coupled technology have been successfully used in engineering, to solve practical problems has a great significance.In short, the paper with lime-electroflocculation coupled technology to deal with the heavy metals lead and zinc smelting waste water is an effective approach and by technological transformation has been successfully applied in Mengzi Mining Co., Ltd. Provides a new approach, new tools and new ideas to solve the smelting wastewater treatment.更多还原