【作者】 保积庆；

【导师】 张启修；

【作者基本信息】 中南大学 ， 有色金属冶金， 2003， 博士

【摘要】 本论文研究内容主要包括两个方面：一、用离子膜技术处理低浓度SO₂烟气吸收液的研究；二、用膜技术处理山西铝厂工业废水的研究。 在所有的低浓度SO₂烟气净化技术中，Wellman—Lord钠碱法已应用于工业脱硫，而且近几年来发展较快，但仍然存在吸收后液中亚硫酸氢钠浓度达不到汽提高浓度SO₂气体的要求，汽提SO₂温度过高，亚硫酸盐氧化严重，产生大量的硫酸盐，造成碱耗增大等诸多问题。 针对以上的问题，首次采用三室双阳膜电解和双极膜电渗析法处理了低浓SO₂钠碱吸收液。 在三室双阳膜电解槽中，按某电厂SO₂烟气吸收液组成配制电解料液，在阳极室硫酸浓度为5mol／L、电流密度在1667A／m²左右、极室液采用泵为驱动力的强制流动方式的条件下进行电解，酸室液pH在3以上时电流效率可达到98％以上，同时碱室液的pH值可达到7.4以上，即达到了再生吸收液的要求，此时酸室液上面气相中SO₂含量在92％以上（65℃）。电解后的酸室液在105℃的温度下蒸发（比Wellman—Lord钠碱法中的115℃低），不但使溶液中亚硫酸氢盐完全分解，蒸发后溶液的pH值恢复到了电解前溶液的pH值，而且蒸发过程中无Na₂SO₃结晶产生。由此可见三室双阳膜电解法完全能解决原工艺中存在的问题。 在双极膜电渗析法处理低浓度SO₂吸收液的研究中，首次提出了用阴膜和双极膜组成二室结构的电渗析器处理低浓度SO₂吸收液的新方法。按某电厂SO₂烟气吸收液组成配制电解料液，在酸、碱室进料比为1：3、电流密度80 mA／cm²、室温（23℃）的最佳条件下电解，酸室液pH＞3时，电流效率达了88.51％以上。 研究结果表明，三室结构双极膜电渗析器和阳膜-双极膜组成的二室结构电渗析器处理低浓度SO₂吸收液时的电流效率低，处理效果差，相同条件下用阴膜-双极膜组成的二室结构电渗析器处理低浓度SO₂吸收液的电流效率高，处理效果中南大学博士学位论文摘要好。阴膜一双极膜组成的二室结构电渗析器在上述电解过程中的能耗要比三室双阳膜电解法低，所以，只要双极膜材料的制备技术过关，用该方法处理低浓度502吸收液更具优越性。 山西铝厂既是用水大户，又是废水排放大户，工业废水排放量为4万m3/d。因此采取有效措施，对各种外排水进行处理，实现水回用是关系铝厂自身前途的大事。论文第二部分是膜法处理工业外排水，实现废水回用，生产不同等级工业用水的研究。 通过反渗透预处理试验，确定了预处理工艺路线为混凝一砂滤。处理后的浊度小于0.INTu，无铁及游离氯，pH值平均为7，全部符合反渗透进水水质要求。与此同时，平均COD值降至32。 在反渗透膜筛选试验中选用了美国海德伦公司、美国osmotric公司的卷式RO膜及国产RO膜。从得出的反渗透的基本工艺参数发现，美国海德伦公司的ESPA 1 RO膜的性能优良。完成了处理量为Zooom3/d大型反渗透工程的计算机模拟设计。 完成了215x550mm2膜堆电渗析制取工业用水试验。试验证明电渗析制取TDS<5 00的一般工业用水是可行的，但用其制取Na+<35mg/L的优质工业用水在经济上不划算。利用美国道公司的卷式NF膜（松散反渗透）进行脱盐试验，表明用NF膜也可以实现制取一般工业用水的目标。更多还原

【Abstract】 Two aspects of pollution are studied in this paper, one is treatment of dilute absorbed solution of SO2 with ion -exchange membrane technique, the other is treatment of industrial waste water from Shanxi Aluminium Plant with membranes.Among the technologies of the treatment of dilute SO2 gas, Wellman-lord natrium-alkali means has been applied in the desulphurizing process for many years. It has much more progress than the others in recent years, but hydrosulfite concentration of the absorbed solution is low, which increase the temperature for steam stripping SO2, and lots of the thermalenergy is used to evaporate water. During the process of steam stripping, the crystal of the sodium sulfite is easy to cause the blockage of pipecine , too much sulphate formed because of oxidation of the sulphite may cause the heavy comsuption ofnatrium.Aimed at the problems above, the three-compartment cation selective membrane electrolysis and dipolar membrane electrodialysis technique are used to deal with the dilute SO2 absorbed solution.In cation-exchange membrane electrolysis experiments with three-compartments cell, the electrolyte was prepared according to the absorbing solution of SO2 from one power plant . The concentration of sulphuric acid in anode compartment is 5mol/L, the current density is about 1667 A/m2, the flow of the solution in the compartment is forced by the pump, the pH of the solution in acid compartment is above 3, and so the current efficiency is more than 98%, and pH value of alkali compartment solution can be up to 7.4, which can satisfy the requirement of regenerating absorption solution, the concentration of SO2 in gas phase is above 92%(at 65), the hydrosulfite in the solution decomposes completely and the pH -value recoveries to that of primary solution,the crystalization of Na2SO3 does not form in the solution after electrolysis in the acid compartment evaperuted at the 105 (the evaperating temperature in Wellman-Lord is 115 ). The problems of original process can be solved with the three-compartment membrane electrolysis cell.The means using two-compartment electrodialysis consisting ofABSTRACTanion-selective and bipolar membrane to treat the absorbed dilute SO2 solution is put forward for the first time . The experimental results show that the optimal working current density is 80mA/cm2.The electrolyte feed composition was prepared in experiment according to absorbed solution of SO2 from a certain power plant. When the ratio of acid compartment and alkali compartment feed is 1 : 3, and at room temperature (23 癈), pH>3, the current efficiency is up to 88.5 1%.The results of experiments show that three-compartment bipolar membrane electrodialysis and two-compartment cation selective-bipolar membrane electrodialysis are not suit to treat the dilute absorbed solution of SO2 because of low current efficiency, under the same conditions, using two-compartment anion selective-bipolare membrane electrodialysis to treat the solution has high current efficienly advantages. The consumption of energy using the two compartment electrodialysis consisting of anion-selective and bipolar membrane to treat solution above is lower than that of the tricompartment cation membrane electrolyser, therefore ,the means using it to treat the absorbed dilute SQ solution is suitable.Shanxi Aluminium Plant not only needs a great deal of water, but also discharges a great deal of waste water .The amount of discharge industrial waste water is 0.4million m3/d. Reutilization of waste water is crucial to the future of the plant. In the second part of this paper, applying the membrane technique to deal with waste water and gain different industry-grade water for the plant has been studied.Through Reverse Osmosis (RO) preprocessing experiment, propressing flow being coagulte-sandfilter is made. The turbidity of the wastewater after preprocessing is less than 0.1NTU, without Fe and free chloric, the average pH-value is about 7, and all of the data are suitable for the requirement of hyper-filtration f更多还原