Article
Engineering, Environmental
Fang Zhang, Ding-Kang Qian, Zi-Qian Geng, Kun Dai, Wei Zhang, Mark C. M. van Loosdrecht, Raymond Jianxiong Zeng
Summary: The hydrolysis of alginate, a main component of extracellular polymeric substances (EPS) in waste-activated sludge, is crucial for enhancing methane production. The alginate-degrading consortia (ADC) showed a significant increase in methane production and biological methane potential, indicating the importance of alginate in EPS for methane recovery. Future research should focus on investigating the microbial changes in ADC for stable digestion of waste-activated sludge.
ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
(2021)
Article
Agricultural Engineering
Jibao Liu, Xianglin He, Hui Zhong, Pei Lei, Junya Zhang, Yufeng Xu, Yuansong Wei
Summary: Thermal hydrolysis reduces the content of methylmercury in sewage sludge, with high temperature promoting both mercury methylation and methylmercury demethylation. Ruminococcaceae, Peptococcaceae, and Lachnospiraceae are potential methylators during hydrolysis and acidogenesis stage, while methylmercury demethylation dominates in the late period of anaerobic digestion.
BIORESOURCE TECHNOLOGY
(2022)
Article
Engineering, Environmental
Jibao Liu, Xianglin He, Yufeng Xu, Zhuang Zuo, Pei Lei, Junya Zhang, Yongguang Yin, Yuansong Wei
Summary: The fate of mercury and MeHg during full-scale anaerobic digestion was investigated, showing that demethylation of MeHg was dominant and likely due to physico-chemical impacts. Microbial methylation or demethylation seemed negligible in terms of MeHg transformation during the anaerobic digestion process.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Engineering, Environmental
Yanfei Tang, Jing Sun, Bin Dong, Xiaohu Dai
Summary: This study attempted to alleviate the inhibitory effect of humic acids (HA) in sludge anaerobic digestion (AD) by directly treating sludge in the digestor with citric acid (CA). Results showed that CA treatment at appropriate dosages could effectively enhance methane production and promote sludge solubilization and hydrolysis. The study suggests that more attention should be given to HA produced and accumulated in AD rather than raw sludge to alleviate the inhibitory effect.
Article
Energy & Fuels
Dominik Andreides, Dana Pokorna, Jana Zabranska
Summary: This study assessed the effects of different syngas loading rates and mechanical stirring on the biomethanation of syngas in a lab-scale continuous anaerobic digester processing sewage sludge. The results showed that mechanical stirring improved the conversion rate of CO and H2, while increased pH resulted in acetic acid accumulation.
Article
Engineering, Environmental
Qian Chen, Bing Zhao, Yuhui Zhang, Fenfen Zhu, Huan Wang, Jiawei Wang, Xingmin Fu
Summary: The environmental risk of heavy metals in sewage sludge from a full-scale Cambi (R) thermal hydrolysis + anaerobic digestion sludge treatment plant was discussed based on four seasons' data. Results showed that the heavy metal concentrations in the sludge increased significantly due to enrichment effect caused by organic degradation, except for Cd. The chemical fractions of different heavy metals varied greatly in the raw sludge, and their residual fractions slightly increased after treatment. Thermal hydrolysis and anaerobic digestion transformed some heavy metal fractions. Deep dehydration reduced the mass of heavy metals in the sludge (less than 10%). The potential ecological risk of heavy metals was low when sludge was applied to soil according to GB 4284-2018, and the accumulation amounts of heavy metals in test soil and rural soil did not exceed GB 36600-2018 and GB 15618-2018.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Environmental Sciences
Xuran Liu, Qian Deng, Mingting Du, Qi Lu, Wenneng Zhou, Dongbo Wang
Summary: The presence of PVC microplastics at environmentally relevant levels does not affect methane production but reduces the toxicity of cadmium. When the concentration of PVC microplastics reaches 30 particles/g TS, methane production recovers to 89.7% in the presence of 5 mg Cd/g TS compared to the control. The adsorption of Cd by PVC microplastics is higher than that of sludge-substrate, reducing the bioavailability of Cd during anaerobic digestion.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Energy & Fuels
Valderi D. Leite, Railson O. Ramos, Paula M. U. Silva, Wilton S. Lopes, Jose T. Sousa
Summary: This study investigated the hydrolysis of carbonaceous and nitrogenous materials in the anaerobic co-digestion process of solid vegetable waste and anaerobic sewage sludge using zero-, first-, and second-order pseudo-kinetic models. The digestion of CODP and subsequent conversion to CODF was found to occur in two stages, with significant differences in the kinetic constants. A simplified kinetic model based on a first-order differential equation was proposed, which showed excellent calibration and validation parameters.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Article
Energy & Fuels
Jakub Mukawa, Tadeusz Pajak, Tadeusz Rzepecki, Marian Banas
Summary: This paper presents the energy potential of biogas obtained from the anaerobic digestion of sewage sludge preceded by thermal hydrolysis. The study shows that this technology can efficiently process sludge and generate a significant amount of biogas. This research is important for meeting energy demand.
Review
Agricultural Engineering
Seyed Mohammad Mirsoleimani Azizi, Faisal I. Hai, Wenjing Lu, Abdullah Al-Mamun, Bipro Ranjan Dhar
Summary: This review comprehensively examines the mechanisms underlying the impacts of (nano)microplastics on anaerobic digestion, including their inhibition/enhancement effects on the process and potential impacts on biochemical pathways, key enzymes, functional genes, and microbial communities. It also highlights the potential environmental risks of biosolids contaminated with (nano)microplastics and outlines knowledge gaps and future research needs for more standardized studies.
BIORESOURCE TECHNOLOGY
(2021)
Article
Environmental Sciences
Yuki Hoshiko, Ryutaro Hirano, Nurul Asyifah Mustapha, Phuong Dong Thi Nguyen, Shuto Fujie, Viviana Sanchez-Torres, Toshinari Maeda
Summary: The role of bacterial interaction is essential in controlling bacterial functions, but its understanding in microbial consortia remains incomplete. This study found that the anticancer agent fluorouracil (FU) inhibited methane production from sewage sludge under anaerobic conditions. The inhibitory effect of FU was observed on acetoclastic methanogens rather than hydrogenotrophic ones, and it was also found to influence the composition of bacterial populations.
Review
Energy & Fuels
V Khanh Nguyen, Dhiraj Kumar Chaudhary, Ram Hari Dahal, N. Hoang Trinh, Jaisoo Kim, S. Woong Chang, Yongseok Hong, Duong Duc La, X. Cuong Nguyen, H. Hao Ngo, W. Jin Chung, D. Duc Nguyen
Summary: Anaerobic digestion (AD) of sewage sludge is an efficient remediation technique, but the presence of complex floc structures and high organic matter content hinder hydrolysis. Pretreatment techniques such as mechanical, chemical, thermal, and biological processes can accelerate hydrolysis and improve AD efficiency.
Article
Green & Sustainable Science & Technology
Lei Zhang, Pu Yang, Kongyun Zhu, Xinran Ji, Jiao Ma, Lan Mu, Fahim Ullah, Wenxiang Ouyang, Aimin Li
Summary: This study investigates the impact of co-treatment of food waste and sewage sludge on the performance of the integrated system. The results show that there is a synergistic enhancement at the optimal ratio, leading to increased methane production and improved combustion characteristics. Additionally, the co-treatment increases the daily energy output and specific energy output of the full-scale plant.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Green & Sustainable Science & Technology
Justyna Gorka, Malgorzata Cimochowicz-Rybicka, Dominika Poproch
Summary: This study investigates the feasibility of utilizing water sludge from a water treatment plant in anaerobic co-digestion with sewage sludge. The experiments confirm that anaerobic digestion of sewage sludge together with water sludge significantly improves biogas production, particularly when water sludge constitutes 30% of the mass of sewage sludge.
Article
Environmental Sciences
Senar Aydin, Arzu Ulvi, Fatma Beduk, Mehmet Emin Aydin
Summary: The occurrences, temporal variations and ecotoxicological risks of 38 selected pharmaceuticals from 7 therapeutic classes have been observed in the anaerobically treated sludge of the urban wastewater treatment plant in Konya, Turkey. The total concentrations of all pharmaceutical compounds ranged from 280 to 4898 μg/kg of dry matter. The dominant therapeutic class was analgesics and anti-inflammatories, and the use of treated sludge as fertilizer in agricultural lands causes continuous contamination of the terrestrial environment by pharmaceuticals.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Agricultural Engineering
Oluwatosin Obata, Joseph C. Akunna, Graeme Walker
BIOMASS & BIOENERGY
(2015)
Article
Agricultural Engineering
J. C. Akunna, A. Hierholtzer
BIOMASS & BIOENERGY
(2016)
Article
Environmental Sciences
Hamed Al Qarni, Philip Collier, Juliette O'Keeffe, Joseph Akunna
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2016)
Article
Biotechnology & Applied Microbiology
A. Hierholtzer, L. Chatellard, M. Kierans, J. C. Akunna, P. J. Collier
JOURNAL OF APPLIED MICROBIOLOGY
(2013)
Article
Environmental Sciences
N. K. Akunwa, M. N. Muhammad, J. C. Akunna
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2014)
Article
Engineering, Environmental
A. Hierholtzer, J. C. Akunna
WATER SCIENCE AND TECHNOLOGY
(2012)
Article
Engineering, Environmental
A. Hierholtzer, J. C. Akunna
WATER SCIENCE AND TECHNOLOGY
(2014)
Article
Engineering, Environmental
Ged Mitchell, Kehinde Oduyemi, Joseph Akunna
WATER SCIENCE AND TECHNOLOGY
(2019)
Article
Engineering, Geological
Carla C. Casas, Carl J. Schaschke, Joseph C. Akunna, M. Ehsan Jorat
Summary: This study investigated the calcium release and reusability of calcium-rich silicate quarry fines in closed and open systems for MICP applications. The results showed that the dissolution of dolerite quarry fines in distilled water at low L/S ratios is a viable option for providing a rich source of calcium in MICP applications.
ENVIRONMENTAL GEOTECHNICS
(2022)
Article
Biotechnology & Applied Microbiology
Oluwatosin Obata, Arlene Ditchfield, Angela Hatton, Joseph Akunna
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
(2020)
Article
Environmental Sciences
Carla Comadran-Casas, Carl J. Schaschke, Joseph C. Akunna, M. Ehsan Jorat
Summary: The study found that cow urine can be a suitable nutrient source for MICP, with urea concentration and stability in fresh and sterilised cow urine suitable for application. The soil response to cow urine treatments was similar to the chemical-based solution, and increasing solution pH resulted in faster activation of ureolytic microorganisms.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Environmental Sciences
Juliette O'Keeffe, Joseph Akunna
Summary: This study provides a simple and cost-effective method for assessing the risks of organic pollutants in waste materials. The results showed little variability in dissolved organic carbon levels in primary sludges from different wastewater treatment plants, but significant differences in secondary sludges. Treated biosolids leached less dissolved organic carbon but had higher proportions of persistent or poorly biodegradable dissolved organic carbon.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Environmental Sciences
F. Jelani, G. Walker, J. Akunna
Summary: The use of aquatic biomass as a potential source for bioenergy production has gained attention worldwide. This study evaluated the production of biogas and bioethanol from marine and freshwater plants using the same pre-treatment methods, and found that both processes can be enhanced with appropriate pre-treatment methods. The effects of thermochemical and enzymatic pre-treatment on selected seaweeds and freshwater macrophytes were investigated, showing that methane biogas and ethanol yields varied depending on the plant species.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Elena Kuzmanova, Nikolai Zhelev, Joseph C. Akunna
Article
Engineering, Chemical
Joseph C. Akunna, Juliette M. O'Keeffe, Richard Allan
DESALINATION AND WATER TREATMENT
(2017)