Hossein Hazrati - Assistant professor, Department of chemical engineering, Sahand university of technology, Tabriz, Iran
Mohammad Rostamizadeh - Assistant professor, Department of chemical engineering, Sahand university of technology, Tabriz, Iran
Hossein Asadi - MS.C student, Department of chemical engineering, Sahand university of technology

In this study treating petrochemical wastewater in a membrane bioreactor was modeled by fuzzy model. To achieve this goal, a lab-scale membrane bioreactor was operated under hydraulic retention times (HTRs) of 20, 15 and 10hrs and solid retention times (SRT) of 5-20 day. The purpose of this study was to examine the efficiency of fuzzy logic in modeling nonlinear and complicated systems which cannot be easily defined with mathematical models. The applied fuzzy inference system was a Mamdani type. There were three inputs (MLSS, HRT, and Time) and three outputs (styrene concentration, ethylbenzene concentration and chemical oxygen demand (COD) removal) in the system. All the inputs and outputs were represented with triangular membership functions. The mean relative error percentage for the model was 1.3% and a correlation factor of 0.99998 was observed. The model results and experimental data proved that a great performance of fuzzy model in predicting the outputs

Modeling, Fuzzy Logic, MBR, Wastewater Treatment