复合式生物除臭反应器处理城市污水处理厂恶臭气体

Odors removal in sewage treatment plant using a combined bioreactor

采用复合式生物除臭反应器处理北京某城市污水处理厂污泥浓缩池和脱水间散发的恶臭气体，研究了反应器对恶臭气体的净化效果和微生物悬浮生长区与附着生长区内的生物特性及对恶臭污染物的去除能力。该污水处理厂的恶臭气体中主要发臭物质为硫化氢和氨，除臭反应器的运行结果表明，在设备稳定运行期间，进气中硫化氢和氨的浓度分别为0．21—22．61mg／m^3和0．1～0．5mg／m^3，而出气中硫化氢浓度在0～0．06mg／m^3，氨浓度为0～0．02mg／m^3。对反应器内部测试表明，微生物悬浮生长区和附着生长区对硫化氢和氨都有一定的去除，但去除机理不同。硫化氢主要被附着生长区的嗜酸性硫细菌生物氧化，少量硫化氢在悬浮区溶于水被中性硫细菌氧化；氨主要在悬浮区靠生物硝化作用去除，少部分氨在附着区被去除，且多因化学中和作用转移到填料所含的水中。

A combined-bioreactor, consisting of a suspension-growth zone and an attachment-growth zone, was developed to treat odors in a municipal wastewater treatment plant in Beijing. The main odor materials emitted from sludge thickening tank and sludge dewatering facility were H2S and NH3. Elimination capacities of odors, effect factors and microbiological characteristic in the individual zone were investigated in this study. Results showed that the inlet concentrations of H2S and NH3 were 0.21 - 22.61 mg/m^3 and 0. 1 - 0.5 mg/m^3 , respectively. During the period of steady treatment, the effluent concentrations reduced to 0 - 0.06 mg/m^3 for H2S and 0 -0.02 mg/m^3 for NH3, H2S and NH3 could be removed effectively in the combined bioreactor. However, their removal mechanisms in the suspension-growth zone were very deferent from that in the attachment-growth zone. Most of H2S were biooxidized by acidophilic Thiobacilli in the attachment-growth zone while less H2S was dissolved in the water or biooxidized by non-acidophilic Thiobacill in the suspension-growth zone. Much more NH3 were removed by nitration in the suspension-growth zone, only few NH3 transferred to aqueous phase by chemical neutralization in the attachment-growth zone.