Ali Naghizadeh - Department of Environmental Health Engineering, School of Public Health, Birjand University of Medical Sciences, Birjand, Iran
Elham Derakhshani - Department of Environmental Health Engineering, School of Public Health, Shahid Beheshti University of Medical Sciences,Tehran, Iran
Ahmad Reza Yari - Center for Environmental Pollutants, Qom University of Medical Sciences, Qom, Iran

Background & Aims of the Study: In order to design membrane bioreactors (MBR)properly, it is essential to comprehend the behavior of microorganisms in such wastewatertreatment processes.Materials & Methods: In this study, a lab-scale MBR process was operated to determinethe biokinetic coefficients of the MBR system under different MLSS concentrations of6800, 7000, 7400, and 7800 mg/l and organic loading rates of 0.5 kg COD/m3/day.Results: The results of this study showed that the yield of microorganisms (Y), theendogenous decay coefficient (kd), the maximum specific growth rate (μmax) and thesaturation constant (Ks) were in the range of 0.67 g VSS/g COD, 0.56 d−1, 1.86 d−1 and 6.65mg COD/l, respectively.Conclusions: The kinetic coefficients in this study can be used to improve the operationand design the MBR system in full scale.

Biokinetic coefficientMembrane bioreactormunicipal wastewater