| At present, coal is the main way to obtain energy in China, but the SO2 pollution caused by coal burning has been a major environmental problem. The most popular way to treatment SO2 pollution is still the limestone lye absorption method,but this treatment mode exists shortcoming such as high equipment investment, difficult disposal by-product etc.So,we must pursue a kind of new desulfurization mode as soon as possible.Biological desulfurization has became a new technical developing broadly because of its simple equipment investment,no by-product,low operate expense and so on.But most research are at primary stage,we have many problems to solve before practical application.This paper studied the optimal culture conditions of desulfurization bacterium (sulfate reducing bacteria,SRB),the bateria domesticated and the preliminary study of desulfurization, absorb immobilization and the best condition,on this basis,we have made a set of biological desulfurization reactor in the lab and carried on the simulation study of dealing with SO2 waste gas. At last we utilized data analysis software to handle parameter optimize.The main research contents and conclusion in this paper as follows:Sulfate reducing bacteria are Gram-negative bacteria,the optimal culture condition of SRB is inoculation amount 10%, pH=7.0, temperature 35℃and culture time 60h, SRB are able to use sodium formate, ethanol, propionate, lactate, glucose and other organic compounds as electron donors for sulfate reduction transformation; SRB can use sulfate, sulfite and thiosulfate as electron acceptor, but can not use sulfur as electron acceptor.It's ablity of SO2 removal rate was 42.6% without domesticated, but through the domesticated by ventilate SO2,the tremoval rate had markly improved to 72.5%.Bio-ceramic is an ideal carrier for desulfurization bacterium, adsorption capacity can up to 23.6mg/g.Use the bio-ceramic to absorb the immobilized desulfurization bacteica,the best bacteria inoculum was 10%,the best pH value was from 6.5 to 7.5.And the result show that:bio-ceramic and medium interaction can make medium pH change toward 6.5 to 7.5,and this confirmed that the bio-ceramic is the ideal carrier for desulfurization bacterium.After immobilized,the bacteria's SO2 removal rate has increased to 87.3%,20.7% higher than pre-immobilized.Made a set of biological desulfurization reactor,used the bio-ceramic as the absorb carrier for the bacteria to membrane desulfurization experiment.The result shows that:when the bio-ceramic filled height of 400mm and the Fe2+ concentration in recycling liquid was 1.0g/L,can promoted the SO2 removal rate of the reactor. In the single factor effect on the desulfurization rate experiment,the best condition were:the inlet concentration of SO2 less than 1500mg/m3,the inlet gas flow less than 100L/h,the volume of circulating liquid spray 15 L/h,and the circulating liquid pH was 7.0,the highest rate of desulfurization can be maintained more than 90%.Finally,we used the SAS data analysis software to design the response surface experiment,optimized the desulfurization parameters of bioreactor,obtained the desulfurization rate of response's equation:After the optimization,the optimum operating parameters were:the inlet concentration of SO2 was 923.55mg/m3,the inlet gas flow was 90.225L/h,the volume of circulating liquid was 13.8837L/h,and the circulating liquid pH was 7.1172.Under this conditions, the desulfurization rate of the bioreactor can reach more than 95%.With the reactor equation we can simulated the effect of the desulfurization tower and the desulfurization rate which change in the environment condition.It provided the reference value to the biological desulfurization as well as the practical application.
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