电絮凝法处理电镀废水中重金属的研究  

An improved approach to treating the electroplating sewage with heavy-metal contaminants via electrocoagulation

作　　者：李萌[1] 张翔宇[1] 

机构地区：[1]中节能六合天融环保科技有限公司,北京100085

出　　处：《安全与环境学报》2016年第1期217-220,共4页Journal of Safety and Environment

摘　　要：采用电絮凝法处理电镀废水中的重金属,考察了电极种类、溶液初始p H值、电流强度、电絮凝时间等因素对重金属离子去除效果的影响。结果表明:金属铁、铝分别作为电极,铝电极对重金属的的处理效果优于铁电极的处理效果;初始p H值在6~9时,重金属离子去除率最高,当p H值低于6或高于9时,去除率下降;随电流强度和电絮凝时间增加,金属离子的去除率增加;在初始p H=6、电流强度为30 A、电絮凝时间为2 min的条件下,电镀废水中Cu2+和Ni2+的去除率分别为98.98%和95.29%,出水重金属离子质量浓度均满足GB21900—2008《电镀污染物排放标准》的规定;以金属铝作为电极,电絮凝时间为2 min时,吨水处理电耗为6 k W·h/m^3。This paper is aimed at introducing an improved approach to treating the electroplating sewage with heavy-metal contaminants via electrocoagulation. For the improved method, we have self-devel- oped electrodes for the concentric tube of iron electrode and aluminum electrode on the basis of the analysis of the water quality to be treat- ed. As a result of our analysis, we have found that the sewage is con- taining copper, nickel, cadmium and zinc. Further analysis let us make out that the residual contents of the copper ion and nickel ion were 41.05 mg/L and 8.7 mg/L respectively, which prove to be over the emission limits of pollutants for electroplating （GB 21900-- 2008）. At the same time, we have also studied the effects of the electrode types, solution pH value, current density and duration time on the removal efficiency of the heavy metal contaminants. In addi- tion, we have also made an exploration of the relation between the operation parameters and the power consumption. All the aforemen- tioned results indicate that the treatment results of the iron electrode tends to be better than that of the aluminum electrode. What is more, the facts show to us that the best removal efficiency can be achieved on the condition when the pH was kept between 6 and 9, below or over which the removal efficiency would suffer retrogression. When the current density is less than 30 A, the removal efficiency of Cu2 ~ and Ni2 ＋ would be found to increase with the increase of the current density. However, when the current density is over 30 A, no obvious increase can be found with the removal efficiency, increasing the du- ration time from 0.5 min to 2.5 rain can also be found very helpful to heighten the removal efficiency of Cu2 ＋ and Ni2 ＋ . For example, on the condition when the initial pH value was 6, the current density was 30 A with the duration time of electrolysis being 2 min, the removal efficiency of Cu2 ＋ and Ni2 ＋ could be expected to reach 98.98 % and 95.29%, respectively. At the same time, the effluent

关 键 词：环境工程学 电絮凝 电镀废水 重金属 去除率 

分 类 号：X703.1[环境科学与工程—环境工程]