Towards a circular economy for stabilized residual from organic municipal solid waste processed at an MBT installation – the potential of SR recycling and recovery

Abstract

Stabilized residual (SR) will not lose its waste status as long as mechanical-biological treatment (MBT) installations deal with residual municipal solid waste. So far, SR has mainly been land-filled, but its recovery could be a new direction for its management. An efficient approach should consider the specific characteristics of SR that can be used for designing SR recycling. Thus, this study aimed to determine the efficiency of organic waste stabilization, detailed biodegradation kinetics and leachate quality. Moreover, the shares of size fractions and SR composition were determined after two-stage aerobic stabilization. Three variants were conducted in a full-scale MBT installation for 8 (SR8), 10 (SR10) and 12 (SR12) weeks with differing aeration intensities in the covered windrows (405–810 m3/h), and optional maturation in uncovered windrows (0–4 weeks). After 8 weeks, the organic waste had become stable. In SR12, the biodegradable waste content was 1.5-times lower and the share of the <10 mm size fraction was 1.3-times higher than in SR8. In the SRs, glass waste constituted over 40% of the 40–10 mm fraction; plastic waste was more than 50% of the >40 mm fraction. Valorization and recovery of valuable materials from specific size fractions of SR should be considered at MBT plants.