Effects of different external carbon sources and electron acceptors on interactions between denitrification and phosphorus removal in biological nutrient removal processes

不同外加碳源和电子受体对生物营养盐去除工艺中反硝化和除磷过程的影响（英文）

The effects of two different external carbon sources （acetate and ethanol） and electron acceptors （dissolved oxygen, nitrate, and nitrite） were investigated under aerobic and anoxic conditions with non-acclimated process bi- omass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/（g MLVSS.h） （MLVSS： mixed liquor volatile suspended solids）, respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO2-N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher deni- trification rates were obtained with acetate （1.4 and 0.8 mg N/（g MLVSS.h）） compared to ethanol （1.1 and 0.7 mg N/ （g MLVSS.h）） for both anoxic electron acceptors （nitrate and nitrite）.

目的:考察两种不同性质的外加碳源(乙酸钠和乙醇)在三种不同的电子受体(溶解氧、硝酸盐和亚硝酸盐)条件下对聚磷菌和异养菌的影响机制。创新点:系统研究了乙酸钠和乙醇这两种外加碳源在溶解氧、硝酸盐和亚硝酸盐三种不同电子受体条件下的释磷、吸磷及反硝化过程。方法:利用具有脱氮除磷功能的活性污泥,开展了一系列一阶段批次试验和两阶段批次试验。一阶段批次试验包括厌氧释磷试验、好氧吸磷试验、硝酸盐及亚硝酸盐利用速率(NUR)试验。两阶段批次试验包括厌氧/好氧试验、厌氧/缺氧试验。通过改变外加碳源的投加条件,如投加类型(乙酸钠和乙醇)、投加环境(厌氧、好氧和缺氧)、缺氧区电子受体(硝酸盐及亚硝酸盐),考察两种不同类型的外加碳源在不同电子受体条件下对除磷和脱氮过程的影响。结论:(1)当乙酸钠作为外加碳源时,在溶解氧、硝酸盐和亚硝酸盐三种不同电子受体条件下均发生了释磷,释磷速率分别为1.70、7.80和3.50 mg P/(g MLVSS·h)。当乙醇作为外加碳源时,三种电子受体条件下均未发现有释磷。(2)无论乙酸钠还是乙醇作为外加碳源,未经驯化的活性污泥聚磷菌均不能利用亚硝酸盐作为电子受体,25 mg NO2-N/L的亚硝酸盐完全抑制了吸磷过程的进行。(3)以硝酸盐作为电子受体时,乙酸钠和乙醇的NUR值分别为2.3和1.5 mg N/(g MLVSS·h),比亚硝酸盐作电子受体的NUR值(分别为1.2和1.0 mg N/(g MLVSS·h))分别高出92%和50%。乙酸钠作为碳源的NUR值总是比相同条件下以乙醇作为碳源的NUR值高。