Seasonal changes in chemical and mineralogical composition of sewage sludge incineration residues and their potential for metallic elements and valuable components recovery

The incineration products composition is dependent on the incineration technology, operating conditions and also on the waste feed composition, which can change seasonally, depending on the temporal growth of the population due to tourism, micro-industry seasonality, intensity of atmospheric precipitation and other factors. Seasonal variations in potentially valuable elements concentrations in incineration products are visible but their overall content is low, therefore this material should not be considered as a source of valuable elements. Due to high content of phosphorus (7.5 wt%) only the fly ash can be considered as a potential source of this critical raw material.