Abstract
The sludge generated in sanitary sewage treatment, mainly during all stages of sewage treatment, is a waste that can be used for energy purposes. The sewage sludge can contain many toxic substances, such as pathogens, metals, and organic contaminants, which can cause severe environmental pollution. Therefore, the adequate treatment and possible energy recovery (generation of electricity and/or heat), in addition to representing a noble destination for sanitary sludge, is aligned with the concept of circular economy. To assess the potential for using sewage sludge as an energy source, various analyses were carried out for its characterization, such as proximate and ultimate analysis, calorific value determination, granulometric analysis, and surface adhesion tension. Among the results obtained, the lower heating value (LHV) stands out, with an average value of about 17 MJ/kg, which is a close result to the LHV of conventional biomass. Furthermore, the tests and sludge characterization results show that the drying method proposed in this study is more interesting than the convective method, given that it produces a smaller particle size in the material, for example.
