Research On Biologically Treated Effluent In Beijing Organic Chemical Plant

This paper presents a water treatment process by which biologically treated effluent in BeiJing organic chemical plant can be recycled as cooling water make-up and the parameter of the process cell.The study focus on resolving the problems as the high conductivity, the high total rigidity,the high organic matter densenity, the high total coliform, the high NH4+-N densenity.After the lab-scale experiment,the processes, biologically aerated filtration(BAF)+ultrafiltration(UF)and coagulation and filtration sedimention tank + ultrafiltration(UF) is recommended.The pilot-scale experiment show that the biologically aerated filtration more efficient than the coagulation and filtration sedimentation tank for biologically treated effluent in BeiJing organic chemical plant. The average COD removal efficiency by biologically aerated filtration is higher than by coagulation and filtration sedimentation tank with the same influent's COD. The main advantage of biologically aerated filtration is high quality effluent achieved at high organic loading. The normalized membrane fouling index for ultrafiltration membranes(MFI-UFn) can measure and monitor the fouling potential of feed water for ultrafiltration membrane. The experiment have measured the MFI-UFn of the effluent of biological areated filtration and that of coagulation and filtration sedimentation tank. Results show that the fouling potential of biological areated filtration is smaller than that of coagulation and filtration sedimentation tank. Biological areated filtration is more efficient as a pre-treatment method for ultrafiltration than coagulation and filtration sedimentation tank. The pilot-scale experiment also discuss the parameters of the biological areated filtration and the ultrafiltrationinstallation.During the experiment, the effluent treated by biological areated filtration and the ultrafiltration always reached the criteria of cooling make-up. The process, biologically aerated filtration(BAF)+ultrafiltration(UF),is recommended by which biologically treated effluent in Beijing organic chemical plant can be recycled as cooling water make-up .