Article
Biotechnology & Applied Microbiology
Bei Li, Chiqian Zhang, Cong Jin, Jinhua Wu, Ping Li
Summary: The leachate from municipal solid waste transfer stations poses challenges due to its complex composition, high concentrations of organic matter, and odorous nature. Anaerobic digestion of leachate can lead to excessive accumulation of volatile organic acids (VFAs), which acidify the digestate and disrupt the anaerobic process. In this study, a facultative anaerobic system with air exposure and an obligate anaerobic system without air exposure were compared to understand the impact of anaerobic degree on intermediate accumulation and process stability. The obligate system showed better performance, with lower VFA concentrations and higher COD removal rates, indicating its potential for stable anaerobic digestion of leachate. Microbial sequencing revealed that VFA-oxidizing bacteria played a crucial role in VFA degradation in the obligate system.
FERMENTATION-BASEL
(2023)
Article
Agricultural Engineering
M. L. Christou, S. Vasileiadis, S. D. Kalamaras, D. G. Karpouzas, I. Angelidaki, T. A. Kotsopoulos
Summary: In this study, the operation of three CTSRs under different OLR conditions revealed that increasing the OLR to raise the C/N ratio can intensify the inhibition of anaerobic processes, especially under high ammonia concentration. Different responses of bacterial and archaeal communities were observed under ammonia stress conditions. Additionally, the dominant methanogenesis route varied depending on the OLR and ammonia concentration.
BIORESOURCE TECHNOLOGY
(2021)
Review
Green & Sustainable Science & Technology
Advait Palakodeti, Samet Azman, Barbara Rossi, Raf Dewil, Lise Appels
Summary: Anaerobic digestion is a mature technology that converts organic waste into biogas, but the released ammonia may have inhibitory effects, necessitating its recovery. Gas-liquid stripping is a technology to recover ammonia, but research on its application to anaerobic digestate of organic wastes is limited. Further research could focus on the effect of digestate composition on ammonia recovery and the impact of stripping gas on ammonia removal.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Environmental Sciences
Qiuxiang Xu, Guojing Yang, Xuran Liu, Jonathan W. C. Wong, Jun Zhao
Summary: Bio-wastes treatment and disposal is a challenging task due to their increasing output. Anaerobic digestion (AD) has been widely used as a promising strategy for bio-wastes treatment, but it is often hindered by internal and external factors, leading to unstable operation performance. Recent research has shown that the addition of hydrochar can improve AD performance by increasing methane yield, improving operation efficiency, reducing heavy metals in digestate, and enhancing digestate dewatering. This review comprehensively summarizes the progress and underlying mechanisms of hydrochar-mediated AD, and highlights the importance of studying the properties of hydrochar for improving AD performance.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Review
Engineering, Environmental
Zi-Yan Li, Daisuke Inoue, Michihiko Ike
Summary: Anaerobic digestion (AD) is a promising technology for pollution control and bioenergy production, but high ammonia concentrations often cause problems. Bioaugmentation has advantages such as rapid microbial response and ease of implementation and can mitigate ammonia inhibition. This review examines previous studies on bioaugmentation for AD and discusses different mitigating mechanisms, as well as temperature conditions and reactor configurations.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Agricultural Engineering
Han Wang, Qun Yan, Xiaoqian Zhong, Irini Angelidaki, Ioannis A. Fotidis
Summary: Anaerobic co-digestion is a strategy for increasing methane production, but substrates rich in proteins and lipids can cause a synergetic co-inhibition effect. This study explored the microbial mechanisms behind the co-inhibition effect and found that ammonia played a major role in affecting methanogens. Decreased abundances of certain microorganisms and critical enzymes confirmed the synergetic co-inhibition effect.
BIORESOURCE TECHNOLOGY
(2023)
Article
Engineering, Environmental
Muhammad Usman, Zhijian Shi, Mengyuan Ji, Shuang Ren, Gang Luo, Shicheng Zhang
Summary: Hydrochar was found to alleviate ammonia inhibition and promote methane production, with the most significant effect observed at high ammonia concentration.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Environmental
Shilei Wang, Zhi Wang, Muhammad Usman, Zehui Zheng, Xiaoling Zhao, Xingyao Meng, Kai Hu, Xia Shen, Xiaofen Wang, Yafan Cai
Summary: Ammonia inhibition is a challenge in anaerobic digestion of nitrogen-rich substrates, but bioaugmentation with specific microbial consortia can restore digestion performance. In this study, two microbial consortia were obtained and applied to a nitrogen-rich AD system, resulting in restoration of performance within 21 days and 83 days, respectively. Methanogenic archaea played a crucial role in the recovery process, and both consortia enhanced the hydrogenotrophic pathway.
Article
Engineering, Environmental
Sergi Astals, Juan Jose Chavez-Fuentes, Gabriel Capson-Tojo, Miroslav Hutnan, Paul D. Jensen
Summary: Studies have shown that LCFA can alleviate the inhibition of ammoniacal nitrogen to a certain extent, possibly due to the formation of a protective layer by LCFA that limits the diffusion of free ammonia into the cell, or provides a localized lower pH around the microbial cell. However, the inhibition of ammoniacal nitrogen and LCFA also involve other inhibitors, and the specific mechanisms are not fully understood.
Review
Green & Sustainable Science & Technology
F. Cheng, C. E. Brewer
Summary: Considerable amounts of organic waste are disposed of in landfills or by incineration, missing opportunities for energy and material applications. Extracting valuable components first from biomass feedstocks is crucial for managing environmental risks. Screening wastes for different conversion methods can enhance profitability and mitigate environmental risks.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Agricultural Engineering
Fred O. Agyeman, Youl Han, Wendong Tao
Summary: This study identified a sequential occurrence of adaptable and unadaptable inhibition in methane production due to ammonia accumulation. The lag phase length representing adaptable inhibition increased exponentially with ammonia concentration, while unadaptable inhibition was best simulated with the Han & Levenspiel model. The distinction between adaptable and unadaptable inhibition provides precise guidance for mitigating ammonia inhibition in biogas production systems.
BIORESOURCE TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Wenjing Tian, Li Gu, Siqi Li, Lirong Zhu, Wen Li, Rui Deng, Feng Liu
Summary: This study evaluated the performance of limited CaO2 addition in maintaining the stability of anaerobic digestion, and found that it significantly reduced VFA concentration, restored pH levels, and enhanced methane production. It also promoted VFA level control and the growth of acetotrophic and hydrogenotrophic methanogeneses.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Engineering, Environmental
Yun Peng, Pingjin Yang, Xiaoming Wang, Yanyan Zhang, Xuya Peng, Lei Li
Summary: The study reveals that deterministic processes may play a larger role in shaping the microbial community than stochastic processes regardless of the level and mode of TAN stress. Under high ammonia stress, acetogens are inhibited, leading to deterioration of AD process function.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Review
Green & Sustainable Science & Technology
Wei Peng, Giovanni Beggio, Alberto Pivato, Hua Zhang, Fan Lue, Pinjing He
Summary: Near-infrared spectroscopy and hyperspectral imaging techniques combined with chemometric method have been applied to address challenges in anaerobic digestion plants, and can be used for monitoring and optimizing process parameters and evaluating quality.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Review
Environmental Sciences
Zhi Wang, Shilei Wang, Wei Zhuang, Jinle Liu, Xingyao Meng, Xiaoling Zhao, Zehui Zheng, Shanshuai Chen, Hanjie Ying, Yafan Cai
Summary: Excessive or insufficient supplementation of trace elements (TEs) affects the progress of anaerobic digestion due to insufficient understanding of digestion substrate characteristics, which influence TEs demand. This review focuses on the relationship between TEs requirements and substrate characteristics, specifically discussing the basis for TE optimization and existing problems, TE deficiency mechanisms for different types of substrates, and regulation of TE bioavailability by substrate characteristics.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
