生物膜法净化低浓度SO2气体的工艺条件研究

On the technical conditions of low-concentrated SO_2 removal by biological membrane

采用生物膜填料塔净化低浓度SO_2气体,研究其适宜工艺条件。结果表明,SO_2进口气体质量浓度2 500-3 500 mg/m^3、气体流量0.1 m^3/h、循环液流量10-12 L/h、24℃、循环液pH<1.7时,生物膜填料塔对SO_2的净化效率可达97.2%以上,对SO_2生化去除量达52-56mg/(L·h)。本研究为生物法脱除烟气中低浓度SO_2提供了参考。

The paper is aimed at reporting our study findings on the technical conditions of low-concentrated SO2 removal by biological membrane in the laboratory. As is known, sulfur dioxide can be removed as nutrition for the biomass concurrent in the biological trickling filter. It can be changed into sulfuric acid, sulfur and cell matter of the biomass, which grows up with the sulfur dioxide to be removal from the imitated flue gas. The said imitated flue gas would go in counter current with the cycling fluid as it moves from the lower position to the higher one through the biological trickling filter, which is designed and made in our group. The conditional parameters of our study can be illustrated as follows： sulfur dioxide mass concentration, gas flux, cycling fluid runoff, temperature and pH value of the cycling fluid. In our experiments, sulfur dioxide mass concentration proves to range from 1 000 mg/m^3 to 5 000 mg/m^3, while the gas flux ranges from 0.1 m^3/h to 0.4 m^3/h. With the range of cycling fluid runoff from 4 L/h to 14 L/h, the temperature should be kept from 18 ℃ to 24℃. In addition, the cycling fluid＇s pH value ranges from 1.4 to 1.9. Our experimental study has now brought about positive results, indicating that the suitable conditions of the study should stand 2 500 - 3 500 mg/m^3 of sulfur dioxide mass concentration, with gas flux being 0.1 m^3/h, the cycling fluid runoff being 10- 12 L/h and the room temperature being 24 ℃ and the pH value of the cycling fluid 〈 1.7. The sulfur dioxide removal efficiency tends to be able to reach 97.2 % with the sulfur dioxide biological removal quantity rising to 52 -56 mg/（L·h） under suitable conditions. Thus, the result can be taken as a valuable reference to low-concentrated sulfur dioxide removal in the flue gas.