(376d) Combination of Ultrasound & Thermal Pretreatment for Sludge Solubilization and Enhanced Anaerobic Digestion

In last two decades, wastewater treatment has been a very important development due to the increasing limitations in water disposal. Simultaneously, the amount of sewage sludge has also increased in accordance with this development. The disposal of sewage sludge or biosolids management from wastewater treatment plants (WWTP) represents a rising challenge for the environment. As such, the simultaneous resource recovery and pollution abatement by utilizing the conversion of biosolids to energy is of great interest. For wet types of biomass, anaerobic digestion (AD) is a proven technology. However, 45-50 % of the solid input is typically converted to biogas, while the rest transforms into a solid residue, which needs to be disposed of. Thus, pretreatment of sludge prior to AD is a common approach to increase the solid reduction and eventually increase the biogas production as well as minimizing the solid residue. Sludge solubilization through cell disruption is the most common approach to enhance the performance of anaerobic digestion with which organic matters of the cell become available for microbial consumption. In this study, the combined effect of thermal and ultrasound pretreatment techniques on waste activated sludge (WAS) has been investigated. The impact of using different sonication times and different temperatures on solubilization as well as Anaerobic digestibility was investigated and reported.