Characterisation of volatile organic compounds (VOCs) released by the composting of different waste matrices

• Published in: Environmental pollution (1987) Vol. 231; no. Pt 1; pp. 845 - 853
• Main Authors: Schiavon, Marco, Martini, Luca Matteo, Corrà, Cesare, Scapinello, Marco, Coller, Graziano, Tosi, Paolo, Ragazzi, Marco
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2017
• Subjects: Air Pollutants - analysis; Biodegradation, Environmental; Bioreactors; Bridged Bicyclo Compounds; Composting; Cyclohexenes; Environmental Monitoring; Food waste; Mechanical-biological treatments; Monoterpenes; Odorants - analysis; Odour; Refuse Disposal - methods; Sewage - analysis; Sewage sludge; Solid Waste - analysis; Terpenes; Volatile Organic Compounds - analysis; Waste Management; Food waste; Mechanical-biological treatments; Composting; Sewage sludge; Odour
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2017.08.096

The complaints arising from the problem of odorants released by composting plants may impede the construction of new composting facilities, preclude the proper activity of existing facilities or even lead to their closure, with negative implications for waste management and local economy. Improving the knowledge on VOC emissions from composting processes is of particular importance since different VOCs imply different odour impacts. To this purpose, three different organic matrices were studied in this work: dewatered sewage sludge (M1), digested organic fraction of municipal solid waste (M2) and untreated food waste (M3). The three matrices were aerobically biodegraded in a bench-scale bioreactor simulating composting conditions. A homemade device sampled the process air from each treatment at defined time intervals. The samples were analysed for VOC detection. The information on the concentrations of the detected VOCs was combined with the VOC-specific odour thresholds to estimate the relative weight of each biodegraded matrix in terms of odour impact. When the odour formation was at its maximum, the waste gas from the composting of M3 showed a total odour concentration about 60 and 15,000 times higher than those resulting from the composting of M1 and M2, respectively. Ethyl isovalerate showed the highest contribution to the total odour concentration (>99%). Terpenes (α-pinene, β-pinene, p-cymene and limonene) were abundantly present in M2 and M3, while sulphides (dimethyl sulphide and dimethyl disulphide) were the dominant components of M1. [Display omitted] •Volatile organic compounds, from composting of waste matrixes, were characterised.•Dewatered sewage sludge (M1), digested (M2) and raw (M3) food waste were selected.•Sulphides and terpenes were the most abundant species from M1 and M2, respectively.•M3 biodegradation produces both sulphides and terpenes, plus ethyl isovalerate.•M3 produces 60 to 15,000 times higher total odour concentration than M1 and M2. Main finding: The composting of untreated food waste may generate a total odour concentration that is 60 and 15,000 times higher than those expected from the composting of dewatered sludge and digested food waste, respectively.