两相厌氧流化床中优势菌种降解硝基苯废水的特性

Degradation characteristics of nitrobenzene wastewater by efficient strains in a two-phase anaerobic fluidized bed reactor

构建了从强化传质与优势菌相结合的两相厌氧流化床生物降解体系，考察了水力停留时间（HRT）与上流速度2种水力特征以及共基质、pH、进水浓度等主要过程因素对优势菌种降解硝基苯的影响。结果显示，反应器在HRT为36h、上流速度为4m／h时获得较好的处理效果；菌种需要pH7．5的条件下以葡萄糖为共基质降解硝基苯，且两者的最佳质量比约为6；当进水硝基苯浓度为50～345mg／L时，对硝基苯平均降解率和降解速率分别达到91．1％和120．9mg／（L·d），且可耐受2．5倍以内的浓度负荷冲击。由此表明良好的反应器水力条件及优势菌种的结合可使高毒性的硝基苯在厌氧条件下有效地降解。

A two-phase anaerobic fluidized bed reactor was established based on effective mass transfer and efficient strains. Hydraulic conditions including hydro-retention time （HRT） and upflow velocity, and key operating factors including cosubstrate, pH and nitrobenzene concentration were investigated. The results showed that reactor had obtained satisfied efficiency when HRT was 36 h and upflow velocity was 4 m/h. Bacteria depended on glucose as cosubstrate and pH should be controlled at about 7.5. The optimal mass ratio of glucose to nitrobenzene was about 6. When initial nitrobenzene concentration was 50 -345 mg/L, average nitrobenzene degradation rate and degradation velocity reached 91.1% and 120.9 mg/（ L· d） , respectively. The reactor could endure 2.5 times of concentration load shock. It suggests that toxic nitrobenzene can be degraded by efficient strains under optimized reactor conditions.