Electrical energy production methods from sludge waste of wastewater treatment plants

The exhaustibility of fossil fuels and the increasing demand for renewable energy sources have brought attention to the recovery of energy from sewage sludge generated in wastewater treatment plants. In this context, various technologies have been developed for utilizing these waste materials in the production of electrical energy. In line with the growing energy demand and the necessity of environmental sustainability, it is of great importance not only to dispose of wastewater sludge but also to evaluate it as a potential energy source. This study comparatively examines widely used technologies for electricity generation from sludge, including anaerobic digestion (biogas production), thermal gasification, pyrolysis, and microbial fuel cells (MFCs). Additionally, based on laboratory analyses, the energy content of the organic matter obtained from a sludge sample with 18.36% dry matter content was calculated. According to these findings, approximately 125,000 kWh of energy could be generated daily from 150 tons of wet sludge. Efficiency and by-product analyses were also conducted for different technologies. It was determined that the energy obtained could meet a significant portion of the facility's electricity demand, and the surplus could be fed into the grid to generate economic revenue. Considering the number of treatment plants and sludge projections across Turkey, such applications could make a significant contribution to sustainable energy production nationwide. In conclusion, this study highlights the potential of sewage sludge energy recovery to contribute both to environmental sustainability and economic efficiency.