嗜热和中温厌氧消化咖啡渣和废活性污泥的动力学特征。
Kinetic characterization of thermophilic and mesophilic anaerobic digestion for coffee grounds and waste activated sludge.
机构信息
Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Dept. of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Aoba-ku, Sendai 980-8579, Japan.
College of Engineering, China Agriculture University, Beijing 10081, China; Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China, Tsinghua University, Beijing 100084, China.
出版信息
Waste Manag. 2015 Feb;36:77-85. doi: 10.1016/j.wasman.2014.11.016. Epub 2014 Dec 17.
This study was conducted to characterize the kinetics of an anaerobic process (hydrolysis, acetogenesis, acidogenesis and methanogenesis) under thermophilic (55 °C) and mesophilic (35 °C) conditions with coffee grounds and waste activated sludge (WAS) as the substrates. Special focus was given to the kinetics of propionic acid degradation to elucidate the accumulation of VFAs. Under the thermophilic condition, the methane production rate of all substrates (WAS, ground coffee and raw coffee) was about 1.5 times higher than that under the mesophilic condition. However, the effects on methane production of each substrate under the thermophilic condition differed: WAS increased by 35.8-48.2%, raw coffee decreased by 76.3-64.5% and ground coffee decreased by 74.0-57.9%. Based on the maximum reaction rate (Rmax) of each anaerobic stage obtained from the modified Gompertz model, acetogenesis was found to be the rate-limiting step for coffee grounds and WAS. This can be explained by the kinetics of propionate degradation under thermophilic condition in which a long lag-phase (more than 18 days) was observed, although the propionate concentration was only 500 mg/L. Under the mesophilic condition, acidogenesis and hydrolysis were found to be the rate-limiting step for coffee grounds and WAS, respectively. Even though reducing the particle size accelerated the methane production rate of coffee grounds, but did not change the rate-limiting step: acetogenesis in thermophilic and acidogenesis in mesophilic.
本研究旨在以咖啡渣和废活性污泥（WAS）为底物，在中温（35°C）和高温（55°C）条件下，对厌氧过程（水解、产乙酸、产酸和产甲烷）动力学进行特征描述。特别关注丙酸降解动力学，以阐明 VFAs 的积累。在高温条件下，所有底物（WAS、磨碎咖啡和生咖啡）的甲烷生成速率均比中温条件下高约 1.5 倍。然而，每种底物在高温条件下对甲烷生成的影响不同：WAS 增加了 35.8-48.2%，生咖啡减少了 76.3-64.5%，磨碎咖啡减少了 74.0-57.9%。基于从修正的 Gompertz 模型获得的每个厌氧阶段的最大反应速率（Rmax），发现产乙酸作用是咖啡渣和 WAS 的限速步骤。这可以通过在高温条件下丙酸降解的动力学来解释，尽管丙酸浓度仅为 500mg/L，但观察到了很长的迟滞期（超过 18 天）。在中温条件下，发现产酸和水解分别是咖啡渣和 WAS 的限速步骤。尽管减小颗粒尺寸可以加速咖啡渣的甲烷生成速率，但不会改变限速步骤：高温下的产乙酸作用和中温下的产酸作用。
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