| 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...
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