School of Environmental Sciences, University of Guelph, Ridgetown Campus, Ridgetown, N0P 2C0, Canada.
School of Environmental Sciences, University of Guelph, Ridgetown Campus, Ridgetown, N0P 2C0, Canada; Centre for Agricultural Renewable Energy and Sustainability, University of Guelph, Ridgetown Campus, Ridgetown, N0P 2C0, Canada.
J Environ Manage. 2021 Apr 15;284:112027. doi: 10.1016/j.jenvman.2021.112027. Epub 2021 Jan 28.
Swine manure and corn stover are abundant agricultural wastes which contribute to greenhouse gas (GHG) emissions, nutrient runoff leading to eutrophication, and a biosafety risk with respect to improper swine manure handling. Anaerobic co-digestion (AcoD) of swine manure and corn stover can mitigate these negative impacts while producing biogas as a renewable energy source. Semi-continuous mesophilic plug flow reactor (PFR operation) was studied during a step-wise increase in organic loading rate (OLR) over the range of 0.25-4.7 kg volatile solids added (VS) m d, which corresponded to total solids content (TS) of 1.5-9.0%. Process stability was observed at all OLR, with the highest total biogas yield and methane content of 0.674 ± 0.06 m kg and 62%, respectively, at 0.25 kg m d. As OLR and TS increased, VS reduction decreased and volatile fatty acids (VFA) increased due to shorter hydraulic retention times (HRT). Hygienization potential was assayed using fecal indicator bacteria (FIB), with some groups being reduced (E. coli, fecal coliforms) and others not (Clostridia spp., fecal enterococci). Lignocellulolytic enzyme activity trended upward as OLR was increased, highlighting changes in microbial activity in response to feeding rate.
猪粪和玉米秸秆是丰富的农业废弃物，它们会导致温室气体 (GHG) 排放、营养物质流失导致富营养化，以及不当处理猪粪带来的生物安全风险。猪粪和玉米秸秆的厌氧共消化 (AcoD) 可以减轻这些负面影响，同时生产沼气作为可再生能源。在逐步增加有机负荷率 (OLR) 的范围内，从 0.25 到 4.7 kg 挥发性固体添加 (VS) m d，即总固体含量 (TS) 为 1.5 到 9.0%，研究了半连续中温推流式反应器 (PFR 操作)。在所有 OLR 下都观察到了过程稳定性，在 0.25 kg m d 的 OLR 下，总沼气产量和甲烷含量最高，分别为 0.674 ± 0.06 m kg 和 62%。随着 OLR 和 TS 的增加，VS 减少，由于水力停留时间 (HRT) 较短，挥发性脂肪酸 (VFA) 增加。使用粪便指示细菌 (FIB) 测定了卫生消毒潜力，一些细菌减少了（大肠杆菌、粪便大肠菌群），而另一些细菌没有减少（梭菌属、粪便肠球菌）。随着 OLR 的增加，木质纤维素酶活性呈上升趋势，突出了微生物活性因进料率而发生的变化。
