Application of aerobic sludge stabilization supported with different pretreatment techniques

In this lab-scale study, alkali and microwave pretreatment methods were used as pretreatment techniques to modify sludge stabilization. The study consists of three main parts. In the first optimization part, optimum operational conditions of microwave pretreatment alone and combined alkaline and microwave pretreatment applications were determined to obtain the most effective sludge stabilization. Central composite design (CCD) was used as a statistical method and disintegration degree (DD) was used as a criteria of solubilization.In the second part of the study, effect of previously determined optimum pretreatment method on performance of organic matter degradation and dewaterability characteristics of mesophilic aerobic digestion as a stabilization process was investigated by operating a lab-scale semi ? batch aerobic digester during 30 d. Results were compared with the results of a parallel unpretreated sludge fed aerobic digester. Inoculum sludge which was provided from aerobic digester of municipal wastewater treatment plant (WWTP) in Manisa, and feed sludge which was provided from return line of secondary sedimentation of domestic WWTP in Izmir were mixed to prepare content of aerobic digester.In the third part of the study, thermophilic aerobic digestion was operated for 30 d, and the effect of thermophilic temperature range on performance of organic matter degradation were evaluated. Analysis were carried out periodically and feeding were carried out daily. Organic matter degradation efficiency of reactors were evaluated according to vector attraction requirements of US Environmental Protection Agency (EPA). As different from other parameters, oxygen uptake rate (OUR) and observed yields (Yobs.) were carried out to demonstrate the accuracy of findings of this study.