The objective of the paper was, inter alia, to determine the impact of coffee grounds on the heat of combustion of their combination with other biological materials. Research on the heat of combustion and calculations of the calorific value were carried out with the use of a KL-12 Mn calorimeter according to the technical specifications and standards PN-81/G–04513 i PN-ISO 1928:2002. Coffee grounds, tea grounds, pine wood and yellow wheat straw were used in the research. The heat of combustion of particular substrates was determined and then their mixtures with coffee grounds in the following proportion were prepared: 75% substrate – 25% coffee grounds, 50% substrate – 50% coffee grounds, 25% substrate – 75% coffee grounds. Calorific value of particular substrates was increasing with the amount of added coffee grounds. Their biggest flow was reported in the mixture of 50%/50% of coffee grounds and wheat straw and the smallest in case of coffee grounds and wood on account of a similar calorific value of both substrates.
A condition of obtaining compost with proper sanitary parameters is achieving the organic recycling process temperature which exceeds 7°C. The objective of the paper was to determine the temperature course in the compost tank for organic recycling of dead poultry in relation to the applied structure forming material. Wheat, oat, barley, rapeseed and corn straw were used as a structure-forming material. A measuring system was equipped with a probe with a temperature sensor with precision of ±0.15°C, transducer and data recorder. Results were prepared with the use of the analysis of variance at the level of significance of α=0.05. Statistically significant differences of the temperature value in the thermophille phase of the composting process between combinations of the experiment were indicated. In all investigated combinations of the experiment, achievement (or exceeding) the temperature value of 70°C of the compost mass was reported.