为了对沉淀池运行过程中的污泥层高度(SBH)进行准确模拟和有效控制,通过沉淀池分层质量平衡方程导出沉淀池分层弥散模型,并利用实测数据确定稳定可靠的SBH算法.以COST 624/682中基准污水厂二沉池为研究对象,利用模型对暴雨天气下恒定回流量和恒定回流比2种措施控制下沉淀池的运行情况进行了稳态和动态模拟.结果表明,在进水流量负荷变化较大的情况下,控制恒定回流比要比控制恒定回流量能更为有效地将SBH和底流SS浓度控制在稳定范围内,进而降低了出水悬浮固体增大的风险.
In order to achieve accurate prediction and effective control of the sludge blanket height (SBH) in real operation, a stable and reliable SBH algorithm was selected based on measured suspended solids (SS) profiles, and then incorporated into a layered and dispersive settling tank model derived from mass balance analysis. The secondary settling tank in COST 6241682 benchmark wastewater treatment plant under storm weather was used for steady-state and dynamic simulations of settling tank operation under two different control strategies, constant return rate and constant return ratio. The later performs were more effectively and steadily in controlling the SBH and underflow SS concentration when large fluctuation of influent hydraulic load occured, thus reducing the risk of effluent sludge escape.