A respirometric method for characterising the organic composition and biodegradation kinetics and the temperature influence on the biodegradation kinetics, for a mixture of sludge and bulking agent to be co-composted

A respirometric method was set up to study kinetics of biological reactions involved in the treatment of organic wastes––sludge mixed with pine barks––by composting. Oxygen consumption rates of this type of mixture were monitored during 10–20 days, using a 10 l respirometric cell kept at constant temperature and moisture. Oxygen consumption kinetics were modelled and organic matter composition was characterised as biomass, easily-biodegradable, slowly-biodegradable and non-biodegradable organic matter. The influence of temperature on kinetics was tested. Results show that this respirometric method is a useful tool for the characterisation of solid organic matter biodegradability and for the modelling of the biological kinetics of the composting process.