A/O脱氮工艺中内循环控制策略的建立与研究

Development and Study of Internal Recirculation Flow Control Strategy in A/O Nitrogen Removal Process

为了在A/O(anoxic/oxic)脱氮工艺中对内循环进行有效的控制,将好氧区生成的硝酸氮回流到缺氧区,实现氮的有效去除,在分析了反硝化反应对进水COD利用效率及反硝化速率影响因素的基础上,得出内循环控制策略就是控制内循环回流量以维持缺氧区末端硝酸氮质量浓度处于最优设定值2.5 mg/L,研究表明该设定值具有很强的鲁棒性,不随进水负荷变化而变化,出水硝酸氮和总氮质量浓度可以实现最低值,同时可大大降低内循环能耗.在上述分析的基础上建立了内循环模糊控制器以期实现污水厂的智能控制.

In order to effectively control internal recirculation flow in A/O (anoxic/oxic) nitrogen removal process, i.e., to make nitrate produced in aerobic zone flow to anoxic zone so as to achieve the effective removal of oxygen, according to the analysis about utilization efficiency of the influent biodegradable COD for nitrate removal and denitrification rate influence factors, the internal recirculation flow control strategy is built, that is, maintaining nitrate concentration at the end of anoxic zone at the best setpoint 2.5 mg/L by controlling nitrate recirculation flow. Studies show that the setpoint appears to be robust towards variation in the influent characteristics; effluent nitrate and total nitrogen concentration can be remained the lowest value, and markedly reduce energy consumption of internal recirculation. In order to achieve intelligent control of wastewater treatment plants, the internal recirculation flow fuzzy controller is developed.