A/O生物脱氮工艺内循环回流和外碳源投加综合控制的优化

为了提高A/O工艺反硝化效果,应用COST/IWA-Benchmark基准对5种内循环回流量和外碳源投加综合控制策略进行了比较.结果表明,控制策略1无论从外碳源消耗量、出水水质,还是从控制器稳定性上都是最优的控制策略,它有2个反馈环路组成,一个环路控制外碳源投加量,从而维持缺氧区出水硝酸氮浓度处于最优设定值2mg/L,另外一个环路控制内循环回流量,维持好氧区出水硝酸氮浓度(根据排放标准确定,一般为8～12mg/L).该策略在低负荷时可以高效利用缺氧区反硝化容量,而在高负荷时通过控制外碳源投量保证出水硝酸氮满足排放标准.

Optimization of Nitrate Recirculation Flow and External Carbon Dosage Integrated Control for A/O Biological Nitrogen Removal Process

In order to improve A/O process denitrification efficiency, five integrated control strategies of nitrate recirculation flow and external carbon dosage for denitrification were proposed and evaluated using the COST/IWA simulation Benchmark. Results show that control strategy No.1 is the best integrated control strategies from both external carbon consumption, effluent quality, and the stability of controller. It comprises two feedback control loops: one is to determine the flow rate of external carbon source, keeping the nitrate concentration at the end of anoxic zone at a pre-specified level 2 mg/L, and the other is to adjust the flow rates of the nitrate recirculation to keep the nitrate concentration at the end of the aerobic zone at a pre-specified level based on the effluent quality (usually 8-12 mg/L). This strategy can guarantee highly effective use of anoxic denitrification capacity in the low-load condition, and meet effluent discharge standards through carbon dosage in the high-load condition.