Comparison of five organic wastes regarding their behaviour during composting: part 1, biodegradability, stabilization kinetics and temperature rise.

This paper aims to compare household waste, separated pig solids, food waste, pig slaughterhouse sludge and green algae regarding their biodegradability, their stabilization kinetics and their temperature rise during composting. Three experiments in lab-scale pilots (300 L) were performed for each waste, each one under a constant aeration rate. The aeration rates applied were comprised between 100 and 1100 L/h. The biodegradability of waste was expressed as function of dry matter, organic matter, total carbon and chemical oxygen demand removed, on one hand, and of total oxygen consumption and carbon dioxide production on the other. These different variables were found closely correlated. Time required for stabilization of each waste was determined too. A method to calculate the duration of stabilization in case of limiting oxygen supply was proposed. Carbon and chemical oxygen demand mass balances were established and gaseous emissions as carbon dioxide and methane were given. Finally, the temperature rise was shown to be proportional to the total mass of material biodegraded during composting.