三级AO耦合工艺低温污水处理脱氮机理

采用分段进水三级AO耦合流离生化工艺处理低温废水,在温度为(10±1)℃条件下,控制HRT为8h,进水流量分配比为3:2:1,污泥回流比为50%,考察耦合工艺对低温污水中污染物的去除效果、反应器内污染物变化规律、各级氮去除规律及系统硝化反硝化性能.研究表明:耦合工艺COD及NH₄⁺-N去除效率均超过90%,TN及TP去除效率达到80%,反应器内生物膜污泥浓度在400～800mg/L之间,系统各级NH₄⁺-N去除率均超过80%,缺氧反硝化脱氮率及好氧同步硝化反硝化脱氮率分别为50.15%和26.05%.受底物浓度及功能菌群数量影响,系统第二级比硝化速率及比反硝化速率均最高.

Analysis on denitrification mechanism of low temperature wastewater treatment by three-stage AO coupling process

The three-stage AO coupled biofilm reactor was used to treat low-temperature wastewater. At the temperature was (10±1)℃, the hydraulic retention time(HRT) was controlled to 8h, the inlet flow distribution ratio was 3:2:1, and the sludge reflux ratio was 50%, then the low-temperature sewage removal effect of the coupled process, the change rule of pollutants in the reactor, the removal rule of nitrogen at each stage, and the system's nitrification and denitrification performance were studied. The removal efficiency of COD and NH₄⁺-N in the coupled process were exceeded 90%, and the removal efficiency of TN and TP reaches 80%. Moreover, the concentration of biofilm in the reactor ranged from 400 to 800mg/L, the removal rate of NH₄⁺-N at all stage of the system were exceeded 80%. The denitrification rate and the rate of aerobic simultaneous nitrification were 50.15% and 26.05%, respectively. Affected by the substrate concentration and the number of functional bacteria, the reactor's second-stage specific nitrification rate and specific denitrification rate were the highest.