Temperature is a key parameter in composting of sewage sludge mixtures due to sanitation requirements. The research conductedby Boniecki et al. (2012) has showed also that temperature ofcomposted mass is the parameter with second (after pH) importance for ammonia emission. However, the increase of temperature results in the growth of ammonia concentration in gaseous emis-sions from composting. All mixtures heated up quickly and reached thermophilic temperatures during the first week of compostingFig