Study On Performance Characteristics Of Membrane Bioreactor For Wastewater Treatment

Membrane bioreactor (MBR) is a new style and high efficiency technology of wastewater treatment, which has a perfect applying prospective in wastewater treatment and reclamation. The basic principle and performance study of MBR is propitious to application and spread.In the study of the influence of hydraulic retention time (HRT) on the effect of wastewater treatment by MBR, the paper concluded that when the HRT was 3h, 2h and 1h, the removal rate of COD was 89.3-97.2%, 88.5-97.3% and 80.0-91.1% respectively. When the HRT were 3h and 2h, the effluent of COD were both below 30mg/L, however, when the HRT was 1h, the effluent of COD was higher, the average was 51.98mg/L. when the purpose was to reach the standard of discharge, the 1h was suggested of HRT and when the purpose was to reach the standard of reclamation, the 2h was suggested of HRT.The membrane bioreactor had a high removal of soybean wastewater, on the steady working condition, the removal rate of COD and BOD was above 96.0% and 98.0%, the average removal rate of TN was 61.7%.Its removal rate of NH₃-N was up to 99.0% or more, the membrane contributes little to the removal of NH₃-N.But the removal rate of TP was unsteady, only 14.7-56.5%.The experimental results showed that the membrane bioreactor system had a good effect on antibiotic wastewater. In the steady working condition, removal rate of COD and BOD was above 97.0% and 98.0%, removal rate of TN was 50.0%, optimal DO and MLSS was about 2-4mg/L,6871-12201mg/L.Membrane pollution sorts and forming mechanism or reasons were analyzed through cleaning experiments. The control methods of membrane fouling were presented. The influence of operational conditions was found out. The correlativity between membrane flux and temperature, pressure (under the condition of temperature 4-30℃and pressure 10³0kPa) was direct proportion.And there was negative linear correlation between membrane flux and MLSS,the relation was determined by mathematical model J=[(0.0007T²-0.0023T+0.5267)ΔP-0.0476T²+2.0118T-17.124]lnMLSS+(0.3274T+4.2352)ΔP-0.4165T²+17.827T-167.36.These provided bases to the control of operational conditions in submerged MBR.