后置短程反硝化AOA-SBR工艺实现低C/N城市污水的脱氮除磷

为了解厌氧/好氧/缺氧(A/O/A)运行的序批式反应器(SBR)中,强化生物除磷(EBPR)与同步短程硝化反硝化(SPND)耦合,并后置短程反硝化的脱氮除磷特性,以低C/N(≤4)城市污水为处理对象,通过优化曝气量和缺氧时间,实现了低C/N城市污水的深度脱氮除磷.结果表明,当好氧段曝气量由1.0 L·min-1降至0.6 L·min-1,缺氧时间为180 min时,出水PO3-4-P浓度由0.06 mg·L~(-1)降至0,出水NH+4-N、NO-2-N和NO-3-N浓度分别由0.18、18.79和0.08 mg·L~(-1)逐渐降低至0、16.46和0.05 mg·L~(-1),TN去除率由72.69%提高至77.97%;随着曝气量的降低,SPND现象愈加明显,SND率由19.18%提高至31.20%;此后,当缺氧段时间由180 min逐渐延长至420 min,出水PO3-4-P、NH+4-N和NO-3-N浓度分别维持在0、0和0.03 mg·L~(-1)左右,出水NO-2-N低至3.06 mg·L~(-1),SND率达32.21%,TN去除性能逐渐提高,TN去除率高达99.42%,实现了系统的深度脱氮除磷.

Denitrification and Phosphorus Removal from Low C/N Urban Sewage Based on a Post-Partial Denitrification AOA-SBR Process

This study focuses on the investigation of the nitrogen (N) and phosphorus (P) removal characteristics of a combination of enhanced phosphorus removal (EBPR) with simultaneous partial nitrification endogenous denitrification (SPND) and post-partial denitrification process. An anaerobic/aerobic/anoxic (A/O/A) operated sequencing batch reactor (SBR) fed with urban sewage was optimized by regulating the aeration rate and anoxic time. Based on this optimization, deep-level nitrogen and phosphorus removals from low C/N urban sewage could be realized. The experimental results show that the effluent PO₄^3--P concentration decreased from 0.06 mg·L^-1 to 0 mg·L^-1, the effluent NH₄⁺-N, NO₂^--N, and NO₃^--N concentrations gradually decreased from 0.18, 18.79, and 0.08 mg·L^-1 to 0, 16.46, and 0.05 mg·L^-1, respectively, and the TN removal efficiency increased from 72.69% to 77.97% when the aeration rate decreased from 1.0 L·min^-1 to 0.6 L·min^-1 and the anoxic duration was 180 min. With the reduction of the aeration rate, the SPND phenomenon became notable and the SND rate increased from 19.18% to 31.20%. When the anoxic duration was extended from 180 min to 420 min, the effluent PO₄^3--P, NH₄⁺-N, and NO₃^--N concentrations stabilized at~0, 0, and 0.03 mg·L^-1, respectively. The effluent NO₂^--N concentration was as low as 3.06 mg·L^-1, the SND rate was~32.21%, the TN removal performance gradually improved, and the TN removal efficiency was as high as 99.42%. Thus, deep-level nitrogen and phosphorus removals could be realized with the SPNDPR-PD system.