*3.1. Composition of Municipal Waste*

Structural research work on mixed waste was performed at the Regional Waste Managemen<sup>t</sup> Plant in Sianów, which has a mechano-biological waste processing installation. The research work comprised the performance of a morphological analysis of two fractions that were mechanically separated in a rotary drum sifter with 90 mm screen mesh. Samples of waste from both fractions amounting to approximately 100 kg were taken for morphological examination. Tests were performed three times. From fractions defined as oversized (fr. > 90 mm) and subscreen (fr. < 90 mm), nine waste components were separated, i.e., biodegradable waste, plastics, paper and cardboard, glass, metals, textiles, wood, composite materials and other. Percentage shares of particular components were determined by their weight and comparison of the partial results to the entire mass of the sample. The shares, which were calculated in that way, indicated percentage by weight (%(w/w)). The percentage shares of the oversized and subscreen fractions in the mixed waste stream separated in the rotary drum sifter were determined from the mass balance of MBTP's mechanical part [44]. The components separated in both fractions were combined, based on the classification criterion for a given group, thus creating Group No II and Group No III. From both groups, samples were taken for physicochemical tests.
