A+OSA活性污泥工艺剩余污泥减量特性研究

Characterisation of Excess Sludge Reduction in an Anoxic + Oxic-Settling-Anaerobic Activated Sludge Process

采用自动热量计对Anoxic（A）＋oxic-settling-anaerobic（OSA）系统解偶联池进出污泥进行热值分析,以考察污泥量变动与能值变动的相互关系;通过解偶联池参数调整,了解污泥减量趋势,结合能量和物质平衡与常规水质指标测试,推测减量途径和特性.结果表明,解偶联池水力停留时间为5.56、7.14和9 h时,整个系统污泥减量分别为1.236、0.771和0.599 g/d.进出解偶联池的污泥含能水平发生了变化,随停留时间增加出流污泥的单位热值有高于进流污泥单位热值的趋势：5.56 h时,进出水热值没有显著差异;7.14 h时,进出水热值差值在99-113 J/g之间;9 h时,差值在191-329 J/g之间.解偶联池发生了污泥的衰减,停留时间延长,衰减程度越高.A＋OSA系统污泥减量是解偶联池污泥衰减与AO主体反应区污泥产生率变化共同作用的结果.

An energy balance analysis method with auto calorimeter being adopted was introduced to determine calorific values of sludge samples in influent and effluent of uncoupling tank in an anoxic （A） ＋ oxic-settling-anaerobic（OSA） process and a reference system. The affiliation of sludge amount change and its energy content were studied, as well as potential of excess sludge reduction was evaluated through modifying performance of uncoupling tank. The characteristics and causes of sludge reduction in OSA system were deduced according to energy and matter balance analysis. Results show that when the hydraulic retention time （HRT） of uncoupling tank are 5.56 h, 7.14 h and 9 h, the excess sludge reduction of whole A ＋ OSA system are 1.236 g/d, 0.771 g/d and 0.599 g/d respectively. Energy content of sludge flows into and out of the uncoupling tank changes, the specific calorific value of sludge in effluent is inclined to be higher than that in influent with the HRT of the tank increasing ： there isn＇ t any significant difference of sludge calorific values between influent and effluent at 5.56 h, while the differences are in 99-113 J/g at 7.14 h, and 191-329 J/g at 9 h. Sludge in uncoupling tank would decay and longer HRT will result in more attenuation. It could be concluded that excess sludge reduction of A ＋ OSA system is caused by both of sludge decay in uncoupling tank and sludge proliferation in AO reaction zone.