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 ρ_DO 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 ρ_COD is lower than 50×10^-3kg/m³,the effluent ρ_TN 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.