A2/O污水处理工艺中基质转化机理研究

以实际污水培养驯化污泥的小试规模A²/O工艺为研究对象,对系统中基质的转化机理及硝态氮对基质转化的影响进行了批式试验研究.结果表明,在无硝态氮存在于厌氧环境的系统中,厌氧段消耗的COD有51%可被聚磷菌吸收并合成为聚羟基链烷酸(PHAs);缺氧和好氧条件下的比吸磷速率为3.87和6.54 mg/(g·h),利用单位PHAs的吸磷量(r_P/PHA)分别为0.38和0.78.而在有硝态氮存在于厌氧环境的系统中,厌氧段消耗的COD仅有30.8%可被聚磷菌吸收并合成PHAs,61.5%用于还原硝态氮;缺氧和好氧条件下的比吸磷速率为2.24和4.58 mg/(g·h),r_P/PHA值分别为0.35和0.77.同时,在这2个系统中厌氧阶段释放的磷和消耗的COD成良好的线性关系.硝态氮存在于厌氧环境会降低聚磷菌的厌氧释磷速率和效率,使PHAs的合成量减少,从而降低聚磷菌的缺氧和好氧吸磷速率,但并不会影响其吸磷能力.

Research on Substrate Transformation Mechanism in A2/O Process

Based on a laboratory-scale anaerobic-anoxic-oxic process acclimated with real wastewater,substrate transformation mechanism and the effect of nitrate on substrate transformations occurred in the system were investigated.The results indicated that under the anaerobic condition without nitrate,phosphorus-accumulating organisms(PAOs) could take up 51% of COD consumed and store them to PHAs;anoxic and aerobic specific phosphorus uptake rates were 3.87(mg/(g·h)) and 6.54(mg/(g·h)),and the anoxic and aerobic ratios of phosphorus uptake and PHAs utilized,r_P/PHA, were 0.38 and 0.78,respectively.While under the anaerobic condition containing nitrate,only 30.8% of COD consumed was taken up by PAOs and 61.5% was used as the denitrifying carbon source;specific phosphorus uptake rates of anoxic and aerobic sludge were 2.24(mg/(g·h)) and 4.58(mg/(g·h),) and the r_P/PHA under the anoxic and aerobic conditions were 0.35 and 0.77,respectively.Furthermore,in both systems,there was a good linear relationship between COD consumption and phosphate release under the anaerobic condition.The nitrate existed in the anaerobic condition could decrease anaerobic phosphorus release rate and efficiency of PAOs,resulting in a decreased amount of PHAs synthesis and consequently affecting anoxic and aerobic phosphorus uptake rates.However,phosphorus uptake capacity was not influenced by nitrate and the amount of PHAs synthesized in the anaerobic stage.