亚硝氮对厌氧/好氧SBR反应器活性污泥吸磷性能的影响(英文)

INFLUENCE OF NITRITE ON PHOSPHORUS UPTAKE BY ACTIVATED SLUDGE FROM ANAEROBIC-AEROBIC SEQUENCING BATCH REACTOR

以SBR反应器在厌氧/好氧条件下培养的活性污泥为对象进行批次试验,研究了不同浓度NO2--N对缺氧吸磷的影响。结果表明:NO2--N可以作为缺氧吸磷的电子受体,但吸磷速率和吸磷量均低于好氧吸磷。反应开始时的NO2--N浓度对反应过程影响很大,本次试验中NO2--N浓度为20 mg·L-1时缺氧吸磷量和吸磷速率达到最高,低于该值时吸磷量和吸磷速率随着NO2--N浓度的提高而增加,但会出现“二次释磷”现象;高于该值时吸磷量和吸磷速率随着NO2--N浓度的提高而减少;NO2--N浓度达到80 mg·L-1时没有发现对吸磷过程的抑制作用;反应器在厌氧/缺氧条件下连续运行,DPB的释磷和吸磷能力很快丧失。

The effect of nitrite on anoxic phosphorus uptake was investigated in detail to obtain a better insight into denitrifying phosphorus removing bacteria （DPB）. Batch experimental tests under different nitrite concentrations were carried out using activated sludge cultivated in a sequencing batch reactor （SBR） under anaerobic-aerobic condition. The experi- mental results confirmed that nitrite could be used as electron acceptor for anoxic phosphorus uptake. However, for nitrite a relatively small amount of phosphorus was taken up compared to aerobic phosphorus uptake. The result also confirmed that the activity of anoxic phosphorus uptake is associated with the initial loading amount of nitrite. There was an optimal nitrite concentration at the beginning of experiment （in this study was 20 mg·L^-1 ）. If the initial concentration were below the optimal one, the amount of anoxic phosphorus uptake increased with an increase in the nitrite concentration, otherwise it would decrease. It was suggested that nitrite was not an inhibitor to phosphorus removal process even the con centration was 80 mg · L^-1 high. Instead, it was an alternative electron acceptor to oxygen or nitrate. However, under continuous anaerobie-anoxic condition DPB lost the abilities of phosphorus release and uptake rapidly.