Article
Engineering, Environmental
Huan Liu, Xuan Li, Zehao Zhang, Long D. Nghiem, Li Gao, Qilin Wang
Summary: This study demonstrated that pretreatment of secondary sludge with free ammonia enhanced volatile solids destruction and methane production in semi-continuous anaerobic digestion systems. The FA pretreatment also improved sludge dewaterability and pathogen removal efficiency, while reducing the volume of dewatered sludge and overall cost. These findings suggest a promising strategy to enhance sludge reduction in anaerobic digestion processes.
Article
Green & Sustainable Science & Technology
Wei Wei, Zhijie Chen, Derek Hao, Xiaoqing Liu, Bing-Jie Ni
Summary: This study improved daily methane production and VS destruction in continuous anaerobic digestion by using natural diatomite as a mediator. The microbial community in the digester shifted towards a more favorable direction, and process modeling showed increased hydrolysis rate and biomethane potential. Natural diatomite mitigated ammonia inhibition and enhanced electron transfer for WAS-to-methane conversion.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Green & Sustainable Science & Technology
Harold Leverenz, Russel Adams, Jessica Hazard, George Tchobanoglous
Summary: The state of California has passed legislation to divert organic materials from landfills to reduce methane emissions. This paper focuses on two pilot studies designed to remove ammonia from digester effluent using a thermal stripping column. The studies found that performance was similar with and without caustic addition.
Article
Green & Sustainable Science & Technology
Xiaoqian Zhang, Igor M. Lopes, Ji-Qin Ni, Yongping Yuan, Chi-Hua Huang, Douglas R. Smith, Indrajeet Chaubey, Shubiao Wu
Summary: This study investigated the performance of anaerobic digestion in converting animal and agro-industrial wastes into organic fertilizers over a long-term field conditions. The results showed significant variability in converting feedstock in the three digesters, with differences in pH, total solids, and ammonium nitrogen concentrations. The impact of anaerobic digestion on metal concentrations was mixed and insignificant due to large concentration variations.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Agricultural Engineering
Mathu Indren, Cristian H. Birzer, Stephen P. Kidd, Tony Hall, Paul R. Medwell
Summary: The study demonstrates that high dosages of pristine biochar can improve the performance of high-solids anaerobic digesters, while low dosages and re-used biochar may not have significant effects.
BIOMASS & BIOENERGY
(2021)
Review
Environmental Sciences
Xiangkun Li, Changkuo Liu, Hongwei Xie, Yujie Sun, Shiwei Xu, Gaige Liu
Summary: Thermal hydrolysis (TH) pretreatment, used in anaerobic digestion (AD), has been proven effective in the laboratory and utilized in engineering. However, the properties of AD liquid (ADL), such as high organic matter and ammonia nitrogen concentration, present challenges in subsequent treatment. To overcome this, the autotrophic nitrogen removal (ANR) process is developed. This paper reviews the TH-ADP and ANR mechanisms, addresses difficulties in treating TH-ADL, evaluates current research status, and proposes potential solutions.
Article
Engineering, Environmental
Lirong Zhu, Baocun Wu, Yongli Liu, Jianrui Zhang, Rui Deng, Li Gu
Summary: This study aimed to enhance the conversion of organics to methane in the semi-continuous anaerobic digestion of food waste by using CaO2 and magnetite. The results showed that the addition of CaO2 and magnetite increased methane production and optimized the relationship between fermentation bacteria and methanogenic archaea, leading to an overall improvement in methane production.
Article
Green & Sustainable Science & Technology
Abdul Haq, Ayesha Malik, Alam Khan, Joseph E. Weaver, Ling Wang, Haji Khan, Samiullah Khan, Aamer Ali Shah, Safia Ahmed, Asif Jamal, Francis L. de los Reyes III, Malik Badshah
Summary: The study shows that methanol-extracted residues from Jatropha curcas seeds can produce more biogas during anaerobic digestion, with a higher relative abundance of acetogenic bacteria. Additionally, anaerobic digestion of Jatropha seeds can achieve higher biogas yield at specific organic loading rates and hydraulic retention times.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Energy & Fuels
Xiaoguang Liu, Qian Wang, Yuanzhi Tang, Spyros G. Pavlostathis
Summary: The study evaluated the impact of inter-stage hydrothermal treatment on sewage sludge mixture digestion and found that it increased the ultimate biodegradability of the sludge, but did not significantly affect the overall methane production compared to pre-treatment. Different digestion configurations showed varying performance in methane production, solids reduction, nutrient transformation, and energy balance. Further research is needed to optimize the inter-stage hydrothermal treatment process for efficient energy recovery in sewage sludge digestion.
Article
Agricultural Engineering
Monika Yadav, Vivekanand Vivekanand
Summary: In this study, chitinolytic bacteria were used for bioaugmentation of fungal pretreated agricultural residues to enhance biogas production. Batch and continuous experiments showed that the addition of chitinolytic bacteria to wheat and pearl millet straw pretreated with Chaetomium globosporum resulted in increased biogas yield. Microbial community analysis revealed higher abundance of methanogens in reactors running with pretreated wheat straw, mainly consisting of Firmicutes, Bacteroidetes, Proteobacteria phyla.
BIORESOURCE TECHNOLOGY
(2021)
Article
Engineering, Environmental
Benton Otieno, Seth Apollo
Summary: Vinasse treatment can be effectively achieved by combining anaerobic digestion (AD) with ozonation technology to remove COD and color. Kinetic analysis suggests a recommended ratio of 20:1 between anaerobic and ozonation reactor units. Application of bioenergy from AD can lead to 50% energy savings in the combined system.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Environmental Sciences
Francesco Bianco, Halil Senol, Stefano Papirio
Summary: The study found that the hydrothermal-alkaline pretreatment is an effective method to improve the biomethane production of chestnut shell, significantly enhancing the biodegradability of CS and suitable for future large-scale applications.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Materials Science, Paper & Wood
Wei Zhao, Chen-Yu Zhou, Jun Zhang, Dun-Qiu Wang
Summary: The effects of total solids contents and inocula on the semi-continuous high-solids anaerobic digestion of cassava pulp were studied. Digestate from cassava pulp digestion showed better buffering capability and higher specific methane yields compared to sewage sludge inoculum.
Article
Engineering, Environmental
Fabrizio Sabba, Patrick McNamara, Eric Redmond, Caitlin Ruff, Mike Young, Leon Downing
Summary: This study investigates the mechanism of nitrogen removal and microbial community in post-aerobic digestion (PAD). The results show that nitrite is the dominant nitrogen removal mechanism and ammonia oxidizing bacteria are more abundant in the microbial community.
WATER ENVIRONMENT RESEARCH
(2022)
Article
Engineering, Environmental
Angelica Guerrero Calderon, Haoran Duan, Xiaoguang Chen, Ziping Wu, Wenbo Yu, Carlos E. Silva, Yijing Li, Sohan Shrestha, Zhiyao Wang, Jurg Keller, Zhongwei Chen, Zhiguo Yuan, Shihu Hu
Summary: The study found that Free Nitrous Acid (FNA) pre-treatment can effectively improve anaerobic digestion (AD) performance under different concentrations and durations, with the optimal condition being FNA concentration of 7.2 mgN/L and treatment duration of 24 hours. Changes in microbial communities supported the observation of enhanced sludge degradation with increasing FNA concentrations, but there were inconsistencies between short-term solubilization results and long-term AD performance.