电镀工业园区电镀废水反渗透膜浓水处理试验研究

发布时间：2018-03-29 00:33

本文选题：电镀废水　切入点：反渗透浓水　出处：《湖南大学》2015年硕士论文

【摘要】：电镀工业已经成为我国现代工业体系中不可缺少的重要组成部分,在电镀过程中会产生大量易对环境造成严重危害的电镀废水。近年来,各地根据当地受纳水体环境管理需要,要求企业执行更为严格的排放标准。另外,地方为了发展循环经济,节约生产用水,降低成本,减少排污量,要求电镀企业工业水回用率不低于60%。这样,电镀废水分质分流处理后采用膜深度处理是必然的选择,反渗透后35%~40%的浓水达标处理成为企业普遍面临的一个技术难题。针对电镀工业园区电镀废水反渗透膜后浓水难于处理的问题,本课题依托国家水体污染控制与治理科技重大专项(2012ZX07206-002)中的子课题“工业区排水对水源型河流风险控制技术集成与综合示范”,采用臭氧氧化-曝气生物滤池(BAF)组合工艺处理电镀废水反渗透膜浓水。以佛山顺德某电镀工业园区的电镀废水反渗透浓水为处理对象,在臭氧氧化单元,考察了废水初始p H、臭氧气体质量浓度和反应时间等因素对臭氧氧化效果的影响以及臭氧氧化处理反渗透膜浓水的处理效能,初步探讨了臭氧氧化电镀废水反渗透膜浓水的动力学和反应机理;在BAF单元,以臭氧预氧化后的反渗透膜浓水为对象,研究了水力停留时间和气水比等因素对BAF单元COD去除效果的影响;最后在臭氧-BAF组合工艺的最佳运行工况下,根据运行的处理效果讨论了组合工艺处理反渗透膜浓水的可行性。臭氧氧化实验表明,臭氧氧化处理反渗透膜浓水的最佳工艺参数:废水初始p H值为10,臭氧浓度为31.96mg/L,反应时间为40min。在最佳工况条件下,臭氧氧化反渗透膜浓水过程中,随着处理时间的延长,p H值由10逐渐降低到8左右;同样随着处理时间的延长,TOC浓度也逐渐降低,和COD的去除规律一致;废水的可生化性由初始时的0.08提高到0.32,为后续的生化处理创造了良好的条件。同时,通过分析讨论,臭氧氧化反渗透浓水的反应为一级反应,其表观动力学方程为ln C=5.3662-0.0162t,臭氧氧化反应以间接反应为主,反应中的主导活性氧化物质是羟基自由基(·OH)。BAF实验表明,BAF处理臭氧氧化后的反渗透膜浓水的最佳工艺参数:BAF的水力停留时间为3h,气水比为5:1。当进水COD为180-240mg/L,经组合工艺处理后COD去除率达78.6%,平均出水COD浓度为47mg/L,达到了电镀污染物排放标准中表3标准。
[Abstract]:Electroplating industry has become an indispensable part of the modern industrial system in China. In the process of electroplating, a large number of electroplating wastewater, which can cause serious harm to the environment, have been produced. Enterprises are required to enforce more stringent emission standards. In addition, in order to develop a circular economy, save water for production, reduce costs, and reduce the amount of sewage discharged, local authorities require that the recycling rate of industrial water in electroplating enterprises be not less than 60 percent. It is an inevitable choice to treat electroplating wastewater by advanced treatment of membrane after separate treatment of electroplating wastewater. After reverse osmosis (RO), 35% of concentrated water (40%) has become a common technical problem for enterprises. In view of the difficulty of treatment of concentrated water after reverse osmosis (RO) membrane in electroplating industrial park, This project relies on the sub-project of the national water pollution control and treatment science and technology project (2012ZX07206-002), "Integration and comprehensive demonstration of risk control technology of industrial area drainage to water source river", and adopts the combination of ozone oxidation and biological aerated filter (BAFs). Reverse osmosis (RO) membrane concentrated water was used to treat electroplating wastewater from a electroplating industrial park in Shunde, Foshan. In the ozone oxidation unit, the effects of initial pH, concentration of ozone gas and reaction time on the ozonation effect and the efficiency of ozone oxidation in treating the concentrated water from reverse osmosis membrane were investigated. The kinetics and reaction mechanism of reverse osmosis membrane concentrated water in ozonation electroplating wastewater were preliminarily discussed. In BAF unit, the reverse osmosis membrane concentrated water after ozone preoxidation was taken as the object. The effects of hydraulic retention time (HRT) and air-water ratio on COD removal efficiency of BAF unit were studied. The feasibility of treating reverse osmosis membrane concentrated water by combined process is discussed according to the effect of operation. The optimum process parameters for treating RO membrane concentrated water by ozone oxidation are as follows: initial pH value of wastewater is 10, ozone concentration is 31.96 mg / L, reaction time is 40 min. With the prolongation of treatment time, the pH value decreased gradually from 10 to 8, and the concentration of TOC decreased with the prolongation of treatment time, which was consistent with the law of COD removal. The biodegradability of wastewater was increased from 0.08 at the beginning to 0.32, which created good conditions for subsequent biochemical treatment. At the same time, through analysis and discussion, the reaction of ozone oxidation in reverse osmosis concentrated water was a first-order reaction. The apparent kinetic equation is Ln C 5.3662-0.0162 t, and the ozone oxidation reaction is mainly indirect reaction. The main active oxidant in the reaction was hydroxyl radical (OH).BAF experiment showed that the best process parameter of treating the thick water of reverse osmosis membrane after ozone oxidation by OH).BAF was the HRT of 3 h and the ratio of air to water of 5: 1.When the influent COD was 180-240 mg / L / L, the optimum process parameters were as follows: 1: 1, when the influent COD was 180-240 mg / L), The removal rate of COD was 78.6 and the average concentration of COD in effluent was 47mg / L, which reached the standard of Table 3 of the discharge standard of electroplating pollutants.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X781.1

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