THERMOGRAVIMETRIC AND DIFFERENTIAL THERMAL ANALYTICAL INVESTIGATIONS ON SEWAGE FARM SOILS

Soil substrates of sewage farms (inflow of sewage areas) and of closed savage farms were investigated by means of thermogravimetry and diffe rential thermal analysis. The results were compared with those obtaine d for control samples from outside the savage farms. The organic matte r of actively used sewage areas (inflow) contains a remarkable amount of easily oxidizable compounds brought to the inflows by suspended mat ter. Beside these compounds, macromolecular organic substances predomi nate in the composition of the organic matter and are responsible for an immense heat release in the high temperature range of the thermal s tudies. In the substrates of closed sewage farm inflows or of other se wage farm areas which do not belong to the inflows, the amounts of vol atile and easily oxidizable compounds decrease rapidly. The substrates hardly differ in their reaction temperatures from control samples. Th e influence of single macromolecules on the exothermic oxidation is re duced with increasing humification.