Transformations of water soluble organic materials during thermophilic composting of sewage sludge

Sewage sludge was composted by adding wood chips as a bulking agent. The decomposition of the cellulosic material was ascertained by measuring the transient concentrations of water soluble sugars. The concentrations were found to increase in accordance with the decomposition of the cellulosic material, provided the operating temperature was kept at a level appropriate for the activity of microorganisms.Two kinds of concentrations of water soluble sugars were measured. One was on the concentration of the total sugars determined by the calorimetric method of Dubois. The other was on the concentration of the reducing sugars determined by the Somogyi-Nelson method. The pattern of HPLC (High Pressure Liquid Chromatogram) was determined utilizing a wave length of 280 nm. Time courses of the sugars concentrations and the HPLC pattern enabled us to detect two sources of cellulosic materials: one from the sewage sludge and the other from the wood chips. The former appears to be decomposed by thermophilic bacteria and thermophilic actinomycetes, whereas the latter is decomposed by thermophilic fungi.