Composition of public waste - a case study from Austria.

Waste from public places like parks, pedestrian zones or sidewalks is a visible yet unexploited waste stream. Publications and information on the amounts and makeup of this waste flow are very scarce. To evaluate the resource potential and enable waste management planning, this study aims to assess the quality and quantity of public waste in a detailed waste characterisation campaign. For the first time, an analysis at this level of detail was conducted in a medium-sized town (25,000 inhabitants) in Austria. The sampling campaign included the whole town area. In total, almost 1000 kg of waste was sorted in up to 88 different fractions, which allows the detailed composition of, for example, packaging waste and single-use plastics to be delineated. We found that the amount of waste collected in public street bins is approximately 2.6 % of the total mixed municipal solid waste, resulting in 4.1 kg of public waste per inhabitant annually. The vast majority of this waste is currently collected as mixed waste. The results indicate a high share (52 %) of recyclable materials (glass, metal, paper and lightweight packaging) in mixed public waste, most of which is packaging (44 % of total waste). Other large shares include dog feces (18 % of total waste) and biogenic waste (17 % of total waste). The results lay the foundation for further investigations into, for example, exploiting recycling potential or evaluating possible improvements in separate waste collection in public spaces. Further, the collected data serve as an essential knowledge basis for policymakers and local authorities.