厌氧/好氧SPNDPR系统实现低C/N城市污水同步脱氮除磷的优化运行

为了解同步短程硝化内源反硝化除磷(SPNDPR)系统的脱氮除磷特性,以低C/N城市污水为处理对象,采用延时厌氧(180 min)/好氧运行的SBR反应器,通过联合调控曝气量和好氧时间,考察了该系统启动与优化运行特性.结果表明,当系统好氧段曝气量为0. 8 L·min~(-1),好氧时间为150 min时,出水PO_4~(3-)-P浓度约为1. 5 mg·L~(-1)左右,出水NH_4~+-N和NO_3~--N浓度由10. 28 mg·L~(-1)和8. 14 mg·L~(-1)逐渐降低至0 mg·L~(-1)和2. 27 mg·L~(-1),出水NO_2~--N浓度逐渐升高至1. 81 mg·L~(-1);当曝气量提高至1. 0 L·min~(-1)且好氧时间缩短至120min后,系统除磷、短程硝化性能逐渐增强,但总氮(TN)去除性能先降低后逐渐升高,最终出水PO_4~(3-)-P、NH_4~+-N分别稳定低于0. 5 mg·L~(-1)和1. 0 mg·L~(-1),好氧段亚硝积累率和SND率分别达98. 65%和44. 20%,TN去除率达79. 78%. SPNDPR系统内好氧段好氧吸磷、反硝化除磷、短程硝化、内源反硝化同时进行保证了低C/N污水的同步脱氮除磷.

Simultaneous Nitrogen and Phosphorus Removal Characteristics of An Anaerobic/Aerobic Operated SPNDPR System Treating Low C/N Urban Sewage

This study focused on the nitrogen (N) and phosphorus (P) removal performance optimization of simultaneous partial nitrification-endogenous denitrification and phosphorus removal (SPNDPR) systems. An anaerobic (180 min)/aerobic operated sequencing batch reactor (SBR) fed with domestic wastewater was used for investigating the startup and optimization of SPNDPR by regulating the aeration rate and aerobic duration time. The experimental results showed that at an aerobic aeration rate of 0.8 L·min^-1 and aerobic duration time of 150 min, the effluent PO₄^3--P concentration was about 1.5 mg·L^-1, with the effluent NH₄⁺-N and NO₃^--N concentrations gradually decreasing from 10.28 and 8.14 mg·L^-1 to 0 and 2.27 mg·L^-1, respectively, and effluent NO₂^--N concentration increasing to 1.81 mg·L^-1. When the aeration rate was increased to 1.0 L·min^-1 and the aerobic duration time was shortened to 120 min, the phosphorus removal and partial nitrification-endogenous performance of the system gradually increased, but the total nitrogen (TN) removal performance initially decreased and then gradually increased. The final effluent PO₄^3--P and NH₄⁺-N were stably below 0.5 and 1.0 mg·L^-1, respectively, aerobic nitrite accumulation and simultaneous nitrification-endogenous denitrification (SND) efficiencies were 98.65 and 44.20%, respectively, and TN removal efficiency was 79.78%. The concurrence of aerobic phosphorus absorption, denitrifying phosphorus removal, partial nitrification, and nitrification-endogenous in the aerobic stage of the SPNDPR system ensured the simultaneous removal of N and P from low C/N wastewater.