Calorimetric studies of solid wastes, sewage sludge, wastewaters and their effects on soil biodegradation processes

Calorimetric studies of solid wastes, sewage sludge, wastewaters and their environmental effects focus on three main research areas. The first research area involves determination of selected thermal and physical parameters characterizing the above substances, such as specific heat, thermal conductivity and others. The second area covers processes of total or gradual destruction of the examined substances at a fixed composition of the gaseous phase. The methods applied in this case enable to determine the heat of combustion or the calorific value of the analyzed material, as well as changes in the rate of heat production, measured by differential scanning calorimetry (DSC). The third area of calorimetric studies covers microbial calorimetry as a method for non-destructive monitoring of organic matter biodegradation in order to measure the kinetic and thermodynamic parameters of the investigated processes, i.e., wastewater treatment, composting and decomposition of organic soil matter, as well as to determine the stability of wastes. This paper describes, based on available literature data, the major directions of investigations, using different calorimetric methods, of solid wastes, sewage sludge and wastewaters and additionally their effects on soil microbial processes. The paper also presents the selected calorimetric studies and analyses the biodegradation kinetics of organic wastewaters and glucose decomposition in the presence of phosphogypsum in different soils.