短程硝化-强化生物除磷序批式反应器处理畜禽养殖废水

Partial nitrification-enhanced biological phosphorus removal of a sequencing batch reactor for treating livestock wastewater

畜禽养殖废水有机物水质水量变化大,有机物、氨氮与磷的浓度较高,直接排放会严重危害环境。通过构建厌氧-好氧序批式反应器(SBR)处理预酸化畜禽养殖废水,分析了不同进水负荷条件下反应器对污染物的去除性能和微生物群落结构的变化规律。结果表明:SBR反应器对高负荷进水中TN、PO_(4)^(3-)—P和COD的平均去除率可分别达到64.5%、97.5%和94.5%。反应器出现NH_(4)^(+)—N和NO_(2)^(—)-N亚硝酸同时积累的短程硝化现象,这可能与高进水负荷对氨氧化菌和亚硝酸盐氧化菌的活性和种群的影响有关。与乙酸盐相比,以丙酸盐作碳源时污泥的强化生物除磷活性更高。随着进水负荷的增大,聚糖菌(GAOs)的相对丰度明显升高。四联球状菌(Tetrasphaera)为反应器中始终占优势的聚磷菌(PAOs),对反应器除磷性能有重要贡献。在高有机负荷条件下,SBR内PAOs与GAOs之间不存在明显的底物竞争关系,系统脱氮除磷性能未受影响。

Direct discharge of livestock wastewater seriously harms the environment,due to the significant changes in water quality and quantity it brings forth,and the high concentrations of organic matter,ammonia nitrogen,and phosphorus the waste water contains.Here,changes in pollutant removal performance and microbial community structure of a kind of pre-acidified high-strength livestock wastewater were investigated on laboratory scale by means of the anaerobic-aerobic sequencing batch reactor(SBR)under different influent loading conditions.The results showed that the removal rates of the total nitrogen(TN),orthophosphorus(PO_(4)^(3-)—P)and chemical oxygen demand(COD)in the high load influent processed by the SBR reached 64.5%,97.5%and 94.5%,respectively.The reactor presented shortcut nitrification with simultaneous accumulation of NH_(4)^(+)—N and NO_(2)—N,which may be related to the effect of high influent loading on the activity and populations of ammonia-and nitrite-oxidizing bacteria.The enhanced biological phosphorus removal activity of the sludge was higher when propionate was used as the carbon source instead of acetate.The relative abundance of glycogen accumulating organisms(GAOs)increased significantly with the increase of influent loading.Tetrasphaera was the consistently dominant polyphosphate accumulating organisms(PAOs)in the reactor and contributed significantly to phosphorus removal performance.With a high concentration of organic matter,there was no significant substrate competition between PAOs and GAOs in SBR,and the nitrogen and phosphorus removal performance of the system was not affected.