Performance Comparison of Activated Sludge Systems at Mesophilic and Thermophilic Modes in Treating Dairy Wastewater


In this research, two activated sludgeexperimental laboratoryplants wereconstructed and operated using dairy wastewater. One of these plants were operatedat high temperatures of (40 – 60 oC) “Thermophilic microorganisms reactors",whereas the other one were operated at constant temperature of (25 oC)“Mesophilicreactor”. The resultsshowed that the organic removal efficiency of "Mesophilicreactor" was more than the "Thermophilic reactors" and it decreasedwith increasingthe temperature.The kinetic parameters for the both mode of operations were alsocalculated. The value of the substrate removal rate constant (k) for the "Mesophilic,25ºC" reactor was (0.017 day-1) and it was greater than others for the thermophilicreactors.(k) and (Y) decreased with increasing the temperature. The values of (Ks),(Umax), and (Kd) in the thermophilic reactors were more than the corresponding valuesin the mesophilic reactor and increased with increasing the temperature.