Abstract：
Biosolid management is becoming one of the most crucial issues for wastewater treatment plant (WWTP) operators. The application of the Oxic Settling Anaerobic (OSA) process allows the minimisation of excess sludge production. This study compares conventional activated sludge (CAS) and OSA layouts in a full-scale WWTP (namely, Corleone - Italy). Extensive monitoring campaigns were conducted to assess treatment performances regarding carbon and nutrient removal, greenhouse gas (GHG) emissions, excess sludge production, and biomass activity (by means of respirometric analysis). Results showed that the effluent quality consistently met the Italian discharge limits. However, with the implementation of the OSA process, there was a decrease in ammonium removal efficiency, which could be attributed to reduced nitrifier activity related to reduced biomass production and extended anaerobic conditions affecting the nitrification process. On the other hand, the OSA configuration significantly increased phosphorus removal, indicating a high phosphorus content in the resulting waste sludge. A worsening of the sludge settling properties was observed with the OSA configuration likely due to decreased EPS concentrations. The sludge production in the OSA configuration decreased by 17.3 % compared to CAS. Nitrous-oxide measurements did not show a variation between CAS and OSA configurations, confirming that the OSA process can be a suitable solution for reducing WWTP\'s carbon footprint.
摘要：
生物固体管理正成为污水处理厂（WWTP）运营商最关键的问题之一。氧化沉降厌氧(OSA)工艺的应用允许最小化过量污泥的产生。本研究比较了全尺寸污水处理厂中的常规活性污泥（CAS）和OSA布局（即，柯里昂-意大利）。进行了广泛的监测活动，以评估有关碳和养分去除的处理性能，温室气体（GHG）排放，剩余污泥生产，和生物量活性(通过呼吸分析)。结果表明，出水水质始终符合意大利的排放限值。然而,随着OSA流程的实施，铵的去除效率下降，这可能归因于与生物质产量减少和影响硝化过程的延长厌氧条件相关的硝化活性降低。另一方面,OSA配置显著提高了除磷能力，表明产生的废污泥中磷含量高。用OSA配置观察到污泥沉降性质的恶化可能是由于降低的EPS浓度。与CAS相比，OSA配置中的污泥产量下降了17.3％。一氧化二氮测量没有显示CAS和OSA配置之间的差异，确认OSA工艺是减少污水处理厂碳足迹的合适解决方案。
