Kamaleddin hosseinzadeh - Water and Wastewater Research Center, Applied Chemistry Department, Faculty of Chemistry, Razi University, Kermanshah, Iran.
Aliakbar zinatizadeh - Water and Wastewater Research Center, Applied Chemistry Department, Faculty of Chemistry, Razi University, Kermanshah, Iran.

Among the best currently available techniques for wastewater treatment and reuse, membrane bioreactors (MBRs) and flocculation are important because of their rapidly improving cost/benefit ratio.The focus of the present study is to evaluate the performance of lab-scale membrane bioreactors, CAS-MBR (compartmentalized activated sludge (CAS) system)) as a function of the variables HRT (hydraulic retention time) and MLVSS (mixed liquor volatile suspended solids) and commercially available cationic polyacrylamide (PAM) (Chemfloc 1510C) using jar tests to treating the industrial wastewater were investigated. The optimal conditions for flocculant dosage and pH were determined 20 mg/l and 3-5.25, respectively The main parameter as process response (turbidity removal) was measured and calculated. Interactive effect of two process variables on the process responses was investigated using response surface methodology (RSM). The range of the effluent turbidity achieved 4.0 NTU for the CAS-MBR and final turbidity of 18 NTU could be obtained for Chemfloc 1510C. The results indicated that CAS-MBR, was the most effective for treating industrial wastewater

membrane bioreactors; polyacrylamide; turbidity; RSM