Abstract:
To enhance nutrient removal from low-strength municipal wastewater in a continuous-flow activated sludge (CFAS) process using aerobic granular sludge (AGS) augmentation strategy, a pilot-scale demonstration was configured with a mainstream reactor (anaerobic/aerobic process) and a sidestream sequencing batch reactor for AGS production. The aeration of the mainstream reactor was controlled based on dissolved oxygen (DO) and ammonium concentrations during Phases I and II-III, respectively. During Phase III, an anoxic zone was created in the mainstream aerobic tank. Throughout the demonstration period, excellent sludge settleability in the mainstream reactor (SVI30 ≤ 80 mL g-1) under long sludge retention time conditions (≥12 d) allowed the maintenance of a high mixed liquor suspended solids concentration (≥3000 mg L-1). The total nitrogen (TN) removal ratio improved significantly during Phases II and III (49.3 ± 4.1% and 50.1 ± 10.2%, respectively) compared to Phase I (43.2 ± 5.5%). Low DO concentration (< 0.5 mg L-1) by the ammonium-based aeration tended to increase the simultaneous nitrification and denitrification efficiency (> 40%), enhancing TN removal (> 50%). The reduction of DO and nitrate concentrations in the returning sludge liquor can stabilize phosphorus removal (approximately 80% of the 25th percentile). In addition, the aeration efficiency during Phase III decreased by 26-29% compared to Phase I. These results suggest that the introduction of ammonium-based aeration control to the CFAS using the AGS augmentation strategy could contribute to superior sewerage treatment, including nutrient removal and a low carbon footprint.
摘要:
为了在使用好氧颗粒污泥(AGS)增强策略的连续流活性污泥(CFAS)工艺中增强低强度城市污水中的养分去除,为AGS生产配置了一个主流反应器(厌氧/好氧工艺)和一个侧流顺序分批反应器。在阶段I和II-III期间,基于溶解氧(DO)和铵浓度控制主流反应器的曝气,分别。在第三阶段,在主流好氧池中形成缺氧区。在整个示范期间,在长污泥停留时间条件(≥12d)下,主流反应器(SVI30≤80mLg-1)中出色的污泥沉降性允许维持较高的混合液悬浮固体浓度(≥3000mgL-1)。在第二阶段和第三阶段,总氮(TN)去除率显着提高(49.3±4.1%和50.1±10.2%,分别)与第一阶段(43.2±5.5%)相比。低溶解氧浓度(<0.5mgL-1)的铵基曝气倾向于提高同步硝化反硝化效率(>40%),增强TN去除(>50%)。回流污泥液中DO和硝酸盐浓度的降低可以稳定磷去除(约为第25百分位数的80%)。此外,与第一阶段相比,第三阶段的曝气效率降低了26-29%。这些结果表明,使用AGS增强策略将基于铵的曝气控制引入CFAS可能有助于出色的污水处理,包括营养去除和低碳足迹。