AOA-SBR工艺用于城市污水同步脱氮除磷

SIMULTANEOUS NITROGEN AND PHOSPHORUS REMOVAL FROM MUNICIPAL WASTEWATER BY AN ANAEROBIC/AEROBIC/ANOXIC PROCESS IN SEQUENCING BATCH REACTOR

以城市污水为研究对象,考察了不同COD/N/P对厌氧/好氧/兼氧(AOA)-SBR工艺脱氮除磷效果的影响。经过3个月稳定运行,当COD:N:P=800:24:11时,AOA-SBR工艺对污水中有机物、氨氮和磷的去除率分别为100%、84%和93%。实验通过提高有机物浓度削弱聚磷菌(PAOs)与聚糖菌(GAOs)竞争底物的能力,抑制了PAOs好氧放磷速率。当COD=800mg/L时,GAOs和PAOs厌氧乙酸摄取量之比为1:9。此外,实验采用兼氧/好氧吸磷速率比,对反硝化聚磷菌数量(DNPAOs)进行估算,结果表明AOA-SBR工艺比值明显高于A2O和AO工艺。因此,通过调节进水有机物浓度,可使DNPAOs在AOA-SBR同步脱氮除磷过程中发挥重要作用。

An anaerobic/aerobic/anoxic process （AOA） in sequencing batch reactor（SBR） fed with synthetic municipal wastewater was proposed to investigate the effects of changing feed COD/N/P on the performance of simultaneous COD, nitrogen and phosphorus removal. The AOA-SBR process was stably operated over more than three months. When the ratio of COD：N：P was 800：24：11 ,the average COD, nitrogen and phosphorus removal efficiencies were 100%, 84% and 93%, respectively.It was demonstrated that the increment of carbon substrate had an adverse effect on phosphate-accumulating organisms （PAOs） competing carbon substrate with glycogen-accumulating organisms （GAOs）, which inhibited aerobic phosphate uptake. The ratio of anaerobic acetate uptake by PAO to that by GAO is 1：9. Moreover, the ratio of anoxic phosphate uptake to aerobic phosphated uptake, which indicates the fraction of DNPAOs in total PAOs, was experimentally evaluated. The results indicated that the anoxic/aerobic phosphate uptake of AOA-SBR process was much larger than that of A20 and AO processes, the AOA-SBR process allows DNPAOs to take effective part in simultaneous nitrogen and phosphorus removal when a suitable amount of carbon substrate was supplied.