不同碳源对反硝化过程中亚硝酸盐积累的影响

Effects of Different Carbon Sources on Nitrite Accumulation During Denitrification

采用葡萄糖和乙酸钠对反硝化污泥进行200 d的驯化培养后,通过批次试验研究不同碳源对反硝化过程中亚硝酸盐积累的影响。研究结果表明:采用葡萄糖培养的反硝化污泥以葡萄糖为碳源,反硝化过程中亚硝酸盐积累浓度较低;n(C)/n(N)为5时,NO_(2)^(-)-N最大积累浓度仅为13.79 mg·L^(-1),最大NO_(2)^(-)-N积累率为31.20%。采用乙酸钠培养的反硝化污泥以乙酸钠为碳源,反硝化过程中亚硝酸盐能快速积累,且积累浓度较高;n(C)/n(N)为3,反应至120 min时NO_(2)^(-)-N积累浓度为37.86 mg·L^(-1),NO_(2)^(-)-N积累率达到72.48%;该污泥以葡萄糖为碳源,反硝化过程中亚硝酸盐积累浓度也较高;n(C)/n(N)为3,反应至240 min时,NO_(2)^(-)-N积累浓度为24.41 mg·L^(-1),最大NO_(2)^(-)-N积累率达到52.59%。采用葡萄糖和乙酸钠培养的反硝化污泥中均以Thauera为优势属,Thauera相对丰度分别为58.69%和70.62%。

Glucose and sodium acetate were used as carbon sources to cultivate denitrifying sludge for 200 d. And the effects of different carbon sources on the accumulation of nitrite during the denitrification process were investigated through batch experiments. The results showed that when glucose was used as carbon source in the denitrifying sludge cultured with glucose, the accumulation concentration of nitrite was low during denitrification. At n(C)/n(N)of 5, the accumulation concentration of NO_(2)^(-)-N was only 13.79 mg·L^(-1)and the maximum accumulation ratio of NO_(2)^(-)-N was 31.20%. When sodium acetate was used as carbon source in the denitrification sludge cultured with sodium acetate, nitrite could accumulate rapidly and high accumulation concentration could be observed during the process of denitrification. Under n(C)/n(N)of 3, the accumulation concentration of NO_(2)^(-)-N was 37.86 mg·L^(-1)and the accumulation ratio of NO_(2)^(-)-N reached 72.48% when the reaction time was 120 min. When glucose was dosed to the sludge acclimated with sodium acetate, high accumulation of nitrite was also obtained in the denitrification process. When the n(C)/n(N) was 3 and the reaction time was 240 min, the accumulation concentration of NO_(2)^(-)-N was 24.41 mg·L^(-1)and the maximum accumulation rate of NO_(2)^(-)-N reached 52.59%. The denitrification sludge cultured with glucose and sodium acetate were both dominated by Thaurea, whose relative abundance accounted for 58.69% and 70.62% of the total genera, respectively.