Wei Jia-Min, Huang Hui-Min, Cheng Cheng, Jiang Zhi-Yun, Liu Wen-Ru, Shen Yao-Liang
School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
Jiangsu Collaborative Innovation Center of Water Treatment Technology and Material, Suzhou 215009, China.
Huan Jing Ke Xue. 2019 Apr 8;40(4):1900-1905. doi: 10.13227/j.hjkx.201808063.
In this work, the effects of the sludge retention time (SRT, 35, 25, or 15 d) and pH (7.5, 8.0, 8.5) on denitrifying phosphorus removal were investigated using denitrifying phosphorus bacteria (DPBs) enriched in a sequencing batch reactor (SBR). The results indicated that shortening the SRT from 35 d to 25 d resulted in a decrease in the mixed liquor volatile suspended solids (MLVSS) from 2821 to 2301 mg·L, while the sludge loading rate (F/M) increased from 0.256 kg·(kg·d)to 0.312 kg·(kg·d). Although the quantity of net phosphorus release and net phosphorus uptake decreased at this stage, the rates of anaerobic phosphorus release, anoxic phosphorus absorption, and denitrification reached their highest levels with values of 25.07, 15.92, and 9.45 mg·(g·h), respectively, due to the increased sludge activity. Consequently, the phosphorus content of the sludge increased from 4.78% to 5.33%, and the removal rate of PO-P was stable at above 95% with an average effluent PO-P concentration below 0.5 mg·L. When the SRT was further shortened to 15 d, the MLVSS decreased to values as low as 1448 mg·L, and the proportion of DPBs in the phosphorus accumulating organisms (PAOs) decreased from 82.4% to 65.7%, indicating that the DPBs were gradually washed out from the system due to the excessively short SRT. At this stage, the phosphorus content of sludge decreased to 3.43%, while the rates of phosphorus release, phosphorus absorption, and denitrification also decreased to some extent. When the pH was increased (7.5-8.0), the anaerobic phosphorus release rate and the anoxic phosphorus absorption rate also increased, and reached 25.86 mg·(g·h) and 16.62 mg·(g·h), respectively, at a pH of 8.0. When the pH exceeded 8.0, the phosphorus removal efficiency dropped rapidly, supposedly due to phosphorus chemical precipitation.
在本研究中，利用序批式反应器（SBR）中富集的反硝化聚磷菌（DPB），研究了污泥停留时间（SRT，35、25或15天）和pH值（7.5、8.0、8.5）对反硝化除磷的影响。结果表明，将SRT从35天缩短至25天，混合液挥发性悬浮固体（MLVSS）从2821mg·L降至2301mg·L，而污泥负荷率（F/M）从0.256kg·(kg·d)增至0.312kg·(kg·d)。尽管此阶段净磷释放量和净磷吸收量有所下降，但由于污泥活性增加，厌氧释磷速率、缺氧吸磷速率和反硝化速率分别达到最高水平，值分别为25.07、15.92和9.45mg·(g·h)。因此，污泥磷含量从4.78%增至5.33%，PO-P去除率稳定在95%以上，平均出水PO-P浓度低于0.5mg·L。当SRT进一步缩短至15天时，MLVSS降至低至1448mg·L，反硝化聚磷菌在聚磷菌（PAO）中的比例从82.4%降至65.7%，表明由于SRT过短，反硝化聚磷菌逐渐从系统中被冲出。在此阶段，污泥磷含量降至3.43%，同时磷释放速率、磷吸收速率和反硝化速率也有所下降。当pH值升高（7.5 - 8.0）时，厌氧释磷速率和缺氧吸磷速率也增加，在pH值为8.0时分别达到25.86mg·(g·h)和16.62mg·(g·h)。当pH值超过8.0时，除磷效率迅速下降，推测是由于磷的化学沉淀。
