Composting Research Group (GICOM), Dept. of Chemical, Biological and Environmental Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain; Group of Biological Treatment of Liquid and Gaseous Effluents (GENOCOV), Dept. of Chemical, Biological and Environmental Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
BETA Technology Centre: "U Science Tech", University of Vic-Central University of Catalonia, 08500 Vic, Barcelona, Spain.
Sci Total Environ. 2019 Mar 1;654:311-323. doi: 10.1016/j.scitotenv.2018.11.081. Epub 2018 Nov 9.
Volatile organic compounds (VOCs) and ammonia are some of the compounds present in gaseous emissions from waste treatment facilities that contribute to odour pollution. In the present work, the effect of the residence time on the biological stability of raw sludge (RS) composted in dynamic windrows and the gaseous emissions generated were studied at a full-scale composting plant, aiming to provide specific pollutant emission factors and to determine their variability depending on the composting time. Waste stability and emissions analysis considered both a first phase where mixed RS and vegetal fraction (RS - VF) is actively composted in dynamic windrows and a second standard curing phase in turned piles, which lasted 31 days. Two windrows were operated at 4 days of composting time while two other windrows were operated simultaneously at 14 days composting time. Increasing the residence time leads to a better waste stabilization in the first composting phase, providing a 50% reduction of the Dynamic Respiration Index. A decrease of the ammonia emission factor was achieved when increasing the composting time (from 168.5 g NH·MgRS - VF d to 114.3 g NH·MgRS - VF d), whereas the VOCs emission factor was maintained for the same process conditions (between 26.0 and 28.0 g C-VOC·MgRS - VF d). However, an increase of the emission masses of both pollutants was observed (from 0.16 to 0.39 kg tVOCs·MgRS - VF and from 1.21 to 1.60 kg NH·MgRS - VF). Finally, ammonia and VOCs emissions generated at the curing piles were nearly avoided when increasing the composting time of the first phase.
挥发性有机化合物（VOCs）和氨是废物处理设施排放的气态污染物中的一些化合物，它们会导致恶臭污染。在本工作中，在一个全规模的堆肥厂中研究了停留时间对动态垄沟中原始污泥（RS）堆肥的生物稳定性和产生的气态排放物的影响，旨在提供特定的污染物排放因子，并确定其随堆肥时间的变化。废物稳定性和排放分析考虑了两个阶段：第一阶段是混合 RS 和植物部分（RS-VF）在动态垄沟中积极堆肥，第二阶段是在翻堆堆肥中持续 31 天的标准养护阶段。两个垄沟的堆肥时间为 4 天，而另外两个垄沟同时操作的堆肥时间为 14 天。延长停留时间可在第一堆肥阶段实现更好的废物稳定化，使动态呼吸指数降低 50%。随着堆肥时间的增加（从 168.5 g NH·MgRS-VF d 降低到 114.3 g NH·MgRS-VF d），氨排放因子降低，而 VOCs 排放因子在相同的工艺条件下保持不变（在 26.0 和 28.0 g C-VOC·MgRS-VF d 之间）。然而，观察到两种污染物的排放质量都增加（从 0.16 到 0.39 kg tVOCs·MgRS-VF 和从 1.21 到 1.60 kg NH·MgRS-VF）。最后，当增加第一阶段的堆肥时间时，在养护堆中产生的氨和 VOCs 排放几乎可以避免。
