黏性膨胀下活性污泥的脱氮除磷特点研究

为了深入研究黏性膨胀与丝状菌膨胀的异同, 采用 SBR 反应器, 系统地考察了黏性丝状菌膨胀和丝状菌膨胀状态下污泥的脱氮除磷特点。试验结果表明, 在 pH 7. 2 ～8. 0, 温度 22 ～24℃的条件下, 提高好氧阶段的溶解氧(DO) 可以保证氨氮硝化过程不受黏性膨胀的影响。对于黏性膨胀来说, 黏附在污泥表面的胞外聚合物(EPS)会使絮体内部形成缺氧微环境, 有助于同步硝化反硝化(SND)的发生。其好氧阶段的 SND 率要比丝状菌膨胀高出47. 80% , 导致黏性膨胀污泥的硝化过程易出现亚硝酸盐的积累。黏性丝状菌膨胀比丝状菌膨胀会更加恶化污泥的沉降性能, 且污泥的除磷性能也有退化趋势, 其比释磷速率和比吸磷速率较丝状菌膨胀污泥分别降低了17. 65%和25. 00% 。

Investigation of the Characteristics of Nitrogen and Phosphorus Removal under Viscosity Sludge Bulking

In order to study the similarities and differences between viscosity bulking and filamentous bulking further, nitrogen and phosphorus removal characteristics under these two conditions were investigated systematically by using sequencing batch reactors (SBR). The results show that when pH is from 7. 2 to 8. 0, and temperature is from 22℃ to 24℃, viscosity bulking has no effect n nitrification process through increasing DO concentration during aerobic period. Under viscosity sludge bulking, the anoxic micro-environment caused by adhered EPS is proned to stimulate simultaneous nitrification and denitrification ( SND) happen, and the SND ratio is larger by 47. 80% than that under filamentous sludge bulking. Furthermore, higher SND ratio leads to nitrite accumulation during nitrification process. Sludge settleability under viscosity bulking is worse than that under filamentous bulking, and so is the phosphorus removal performance. The specific PO^3-₄P releasing rate and uptakiug rate under viscosity bulking are lower by 17. 65% and 25. 00% than those under filamentous bulking, respectively.