Schiavon Marco, Martini Luca Matteo, Corrà Cesare, Scapinello Marco, Coller Graziano, Tosi Paolo, Ragazzi Marco
Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, I-38123 Trento, Italy.
Department of Physics, University of Trento, Via Sommarive 14, I-38123 Trento, Italy.
Environ Pollut. 2017 Dec;231(Pt 1):845-853. doi: 10.1016/j.envpol.2017.08.096. Epub 2017 Sep 25.
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.
堆肥厂释放的气味物质引发的投诉可能会阻碍新堆肥设施的建设，妨碍现有设施的正常运行，甚至导致其关闭，对废物管理和当地经济产生负面影响。提高对堆肥过程中挥发性有机化合物（VOC）排放的认识尤为重要，因为不同的VOC意味着不同的气味影响。为此，本研究中对三种不同的有机基质进行了研究：脱水污水污泥（M1）、城市固体废物消化后的有机部分（M2）和未处理的食物垃圾（M3）。这三种基质在模拟堆肥条件的实验室规模生物反应器中进行好氧生物降解。一个自制装置在规定的时间间隔从每个处理过程中采集工艺空气样本。对样本进行VOC检测分析。将检测到的VOC浓度信息与特定VOC的气味阈值相结合，以估计每种生物降解基质在气味影响方面的相对权重。当气味形成达到最大值时，M3堆肥产生的废气总气味浓度分别比M1和M2堆肥产生的废气高约60倍和15000倍。异戊酸乙酯对总气味浓度的贡献最大（>99%）。萜烯类（α-蒎烯、β-蒎烯、对伞花烃和柠檬烯）大量存在于M2和M3中，而硫化物（二甲基硫醚和二甲基二硫醚）是M1的主要成分。
