Abstract:

Based on a laboratoryscale anaerobicanoxicoxic (A/A/O) process acclimated with municipal wastewater as carbon source, the effect of internal return ratio on denitrifying phosphorus removal in the system was investigated at internal return ratio of 100%, 200% and 300%, and anaerobic/anoxic batch experiments were performed to study sludge characteristicsThe results indicated that the contribution of anoxic P removal to total P removal became larger, denitrifying phosphorusaccumulating organisms’ (DNPAOs) anoxic P uptake and denitrification capacity per polyhydroxyalkanoates (PHAs) utilized increased firstly, and then decreased, while anaerobic P release capacity per PHAs accumulated and aerobic P uptake capacity per PHAs utilized were rarely influenced by increasing internal return ratioWhen internal return ratio was set at 200%, denitrifying phosphorus removal and biological nutrient removal efficiency were the highestThe results in the batch experiments also showed that higher or lower nitrate concentrations at the beginning of anoxic stage could influence DNPAOs’ anoxic P uptake and PHAs utilization rates, but their intrinsic characteristics were almost never affected.

摘要：

以生活污水培养驯化污泥的小试规模A/A/O工艺为研究对象，进行了混合液回流比为100%、200%和300%时对反硝化除磷的影响研究，并利用厌氧/缺氧批式试验方法对污泥特性进行单独考察。结果表明，随着混合液回流比的增大，缺氧除磷在系统除磷所起的作用、反硝化聚磷菌缺氧利用单位聚羟基链烷酸（PHAs）的吸磷量和反硝化数量出现先升高后下降，厌氧合成单位PHAs的释磷量和好氧利用单位PHAs的吸磷量并没有受到影响，以200%时反硝化除磷和系统脱氮除磷效果为最好，过高或过低NO₃-N浓度均会影响反硝化聚磷菌的缺氧吸磷速率和PHAs降解速率，但并没有影响其本身所固有的特性。