废水中重金属的电化学原位减量研究

发布时间：2018-05-22 08:25

本文选题：电化学处理系统 + 重金属污染　；参考：《大连海事大学》2017年硕士论文

【摘要】：随着工农业生产的迅猛发展,各种重金属的使用和排放量日渐增多,对环境尤其是水环境造成严重影响。重金属一方面由于微生物毒性会对生物处理作用产生影响,另外大部分重金属在水处理过程中被转移到剩余污泥中,对污泥的资源化利用产生严重影响。因此,高效分离去除废水中的重金属以原位降低剩余污泥中的重金属含量,是含重金属废水处理研究中的关键问题。电化学修复技术具有不需要添加化学物质、二次污染少、可以控制污染物的流向等优点,在污染去除及环境修复中占有重要研究价值。本实验自制电化学处理装置,研究电化学处理对水体中重金属的去除效应。以人工配置的含铜、锌、锰和汞的混合重金属模拟废水,采用Pb02/Ti涂层电极作为反应阳极,系统研究了电流密度、溶液初始pH、电解质浓度等因素对电化学重金属去除效果的影响,从而得到本实验中处理混合金属离子的最佳条件为:电流密度为10mA/cm2、溶液初始pH为2.5-4.5、外加电解质浓度为0.2mol/L,对混合金属可以达到较高的去除效果;金属的性质不同,其去除效率不同,实验中所研究四种金属离子的去除先后顺序依次为:HgCuZnMn。适当延长电解时间有助于溶液中Mn和Zn的去除。单元素电化学处理研究对比表明,不同金属的去除速率不同,在相似的条件下,水中单种金属的去除效率明显高于混合金属中该种金属的去除效率。多种金属的共存时,不同金属的迁移及沉积过程存在一定的竞争影响趋势。动力学分析表明,当电流密度为20mA/cm2、溶液初始pH为2.53、外加电解质浓度为0.1mol/L时,锌的去除过程的反应速率常数为0.6960min-1;锰在电流密度为20mA/cm2、pH为3.55,电解质浓度为0.2mol/L时,其去除过程的反应速率常数为0.4901min-1,均遵循一级动力学反应特征。
[Abstract]:With the rapid development of industrial and agricultural production, the use and discharge of various heavy metals are increasing day by day, which has a serious impact on the environment, especially the water environment. On the one hand, the microbial toxicity of heavy metals will have an impact on biological treatment, and most of the heavy metals will be transferred to surplus sludge in the process of water treatment, which will have a serious impact on the reuse of sludge. Therefore, it is a key problem in the treatment of wastewater containing heavy metals to effectively separate and remove heavy metals from wastewater in order to reduce the heavy metal content in excess sludge in situ. Electrochemical remediation technology has the advantages of no need of adding chemical substances, less secondary pollution, can control the flow of pollutants and so on. It plays an important role in the research of pollution removal and environmental remediation. The removal effect of heavy metals in water by electrochemical treatment was studied. The effects of current density, initial pH of solution and electrolyte concentration on the removal efficiency of electrochemical heavy metals were systematically studied by using a Pb02/Ti coated electrode as the reactive anode in a simulated wastewater containing copper, zinc, manganese and mercury. The results show that the optimum conditions for the treatment of mixed metal ions in this experiment are as follows: the current density is 10 Ma / cm ~ 2, the initial pH of solution is 2.5-4.5, and the concentration of electrolyte is 0.2 mol / L. The removal efficiency is different. The order of removal of the four metal ions studied in the experiment is: HgCuZnMn. Prolonging the electrolysis time is helpful to the removal of mn and Zn in the solution. The results of single element electrochemical treatment show that the removal rate of different metals is different, and the removal efficiency of single metal in water is obviously higher than that in mixed metal under similar conditions. With the coexistence of many metals, the migration and deposition of different metals have a certain competitive effect. The kinetic analysis shows that when the current density is 20 Ma / cm ~ 2, the initial pH is 2.53 and the added electrolyte concentration is 0.1mol/L, the reaction rate constant of zinc removal process is 0.6960 min-1, and when the current density is 20 Ma / cm ~ (-2) pH is 3.55, the electrolyte concentration is 0.2mol/L. The reaction rate constant of the removal process is 0.4901min-1, which all follow the first-order kinetic reaction characteristics.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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