变频控制溶解氧和低温下SBR工艺实时控制策略的实现及中试

针对现今序批式活性污泥法(SBR)污水处理厂大多采用灵活性差的定时控制策略的现状,建立实时控制策略强化SBR工艺的性能,提高低温条件下的系统稳定性.采用体积为8.8m3的中试SBR应用定时控制策略长期处理生活污水,采用变频技术控制SBR曝气阶段ρDO保持恒定,同时在低温条件下考察硝化终点时频率,曝气时间与温度之间的经验关系式,最后建立低温条件下的实时控制策略,并将其应用到中试SBR中.结果表明,实时控制策略在SBR系统中得到成功应用,且在低温条件(11～18℃)下稳定运行100 d,出水ρCOD低于50kg/m3,出水ρTN低于5 g/m3,出水COD和TN平均去除率分别达到80%和95%以上,出水水质达到一级A排放标准.

The Achievement of Real-time Control Strategy in Pilot-scale SBR Process at the Conditions of Low Temperature and Fixed Dissolved Oxygen by Applying Frequency Conversion Technology

In order to solve the problem of poor flexibility of fixed time control strategy applying in most sequencing batch reactor(SBR) wastewater treatment plants nowadays,this research tries to enhance the performance of SBR process with a newly built real-time control strategy and to improve the stability of SBR system at low temperature.A 8.8m3 pilot-scale SBR is operated for treating domestic wastewater with fixed-time control strategy.At the same time,frequency conversion technology is applied to control ρDO of aeration period during the study.This study investigates the empirical expressions of frequency(f),aeration time(t) and temperature(θ) at the endpoint of nitrification under low temperature,and establishes a real-time control strategy and applies it into pilot-scale SBR.Results show that real time control strategy for low temperature is successfully applied in pilot-scale SBR,and was operated more than 100 days under low temperature condition(11～18℃),and the effluent ρCOD is lower than 50×10-3kg/m3,the effluent ρTN is lower than 5×10-3kg/m3,the average effluent COD and TN removal efficiency maintains 80%,95% respectively.The quality of effluent achieves the A in the first grade discharge standard.