Article
Agricultural Engineering
Yan Li, Dongliang Hua, Haipeng Xu, Yuxiao Zhao, Fuqiang Jin, Xu Fang
Summary: The study demonstrates that pretreatment of lignocellulosic materials with organic acids can enhance the production of volatile fatty acids (VFAs), but can also inhibit microbial metabolism when the concentration exceeds a certain limit. The type of organic acids affects the metabolic pathway of VFAs, and hydrothermal-organic acid pretreatment can provide crucial information, especially when considering organic loading rates.
INDUSTRIAL CROPS AND PRODUCTS
(2022)
Article
Energy & Fuels
M. A. Tawfik, W. E. Abd Allah, Atiya Ezzat, M. K. Afify, Ahmed Mahdy
Summary: By co-digesting corn stover with quail manure and alkaline pretreatment, using NaOH, the challenges of low carbon/nitrogen ratio, recalcitrant nature, and enhanced methane production are overcome. The best results were obtained with 50/50 mixture and 2.5% NaOH pretreated corn stover, showing significant lignin reduction, organics solubilization, and methane yield enhancement. The synergistic effect of C/N ratio and hydrolysis rate acceleration was identified as the key contributing factor.
Review
Biotechnology & Applied Microbiology
Swarnima Agnihotri, Dong-Min Yin, Amir Mahboubi, Tugba Sapmaz, Sunita Varjani, Wei Qiao, Derya Y. Koseoglu-Imer, Mohammad J. Taherzadeh
Summary: This article provides a detailed overview of the applications of volatile fatty acids (VFAs) generated from petrochemical and biological routes, highlighting their sustainability and flexibility in various fields.
Article
Engineering, Environmental
R. Bevilacqua, M. Mauricio-Iglesias, S. Balboa, J. M. Lema, M. Carballa
Summary: This study investigates the influence of sugar-to-protein (STP) ratio on anaerobic cofermentation outcomes, finding that glucose had no effect on casein conversion as long as the STP ratio was ≤1, but promoted the production of fatty acids. However, an STP ratio >1 inhibited amino acid consumption and reduced volatile fatty acid production.
ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Shiyan Gu, Ruji Wang, Huige Xing, Mingzhe Yu, Siyu Shen, Liang Zhao, Jiyang Sun, Yi Li
Summary: Low temperature affects the anaerobic digestion of pig manure. As the temperature decreases, gas production becomes more unstable, resulting in lower gas production and delayed gas peak. Stability of SCOD varied at different temperatures, with an increase in SCOD over time at higher temperatures. Accumulation of VFAs varied at different temperatures, with higher temperatures resulting in greater accumulation of volatile acids. The digestion system was dominated by the hydrogen-nutrient methanogenic pathway.
WATER SCIENCE AND TECHNOLOGY
(2022)
Article
Agricultural Engineering
Jinsong Liang, Wei Fang, Jianning Chang, Guangming Zhang, Weifang Ma, Mohammad Nabi, Muhammad Zubair, Ru Zhang, Le Chen, Jianghao Huang, Panyue Zhang
Summary: This study demonstrates the feasibility of long-term rumen microorganism fermentation of lignocellulose for stable volatile fatty acid (VFA) production, achieved by manipulating the bacterial community structure. This finding is of great significance for the practical application of rumen microorganisms.
BIORESOURCE TECHNOLOGY
(2022)
Article
Environmental Sciences
Xiang Zou, Junguo He, Heliang Pang, Pengfei Zhang, Xinlei Pan, Yijie Zhong, Shengye Duan, Xinxin Cui, Xiaodong Xin, Jie Zhang
Summary: The synergistic effect of protease and lysozyme on enhancing anaerobic fermentation efficiency and volatile fatty acids recovery was investigated. Asynchronous dosed enzyme cocktail pretreatment was proven to be a better strategy for solubilization and hydrolysis processes, leading to increased VFAs production.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Energy & Fuels
Ziwei Cheng, David W. Gao, Fiona M. Powers, Ricardo Navar, Juan H. Leal, Oyelayo O. Ajayi, Troy A. Semelsberger
Summary: This study investigates the effect of moisture and feedstock variability on the flow behavior of corn stover biomass particles. The results reveal that the presence of moisture reduces the flowability of the particles, with the 15% moisture sample showing the highest flow energy. Additionally, the surface hydrophobicity of the wall material affects the wall friction angle. Sample B has greater flowability and smaller compressibility compared to sample A.
FRONTIERS IN ENERGY RESEARCH
(2022)
Article
Green & Sustainable Science & Technology
A. A. Ajayi-Banji, S. Sunoj, C. Igathinathane, S. Rahman
Summary: Long lag phase and reactor instability pose challenges for describing and predicting methane yield in upset solid-state anaerobic digestion. Seven kinetic models were used for treatment evaluation, with different models best describing methane yield for different treatments. Predicting optimal hydraulic retention time for the least inhibited treatment can aid in reactor design and methane yield simulation.
Article
Energy & Fuels
Md Mosleh Uddin, Zhiyou Wen, Mark Mba Wright
Summary: This study comprehensively analyzes the economic and environmental impacts of using biochar in anaerobic digestion technology. The research shows that biochar addition can significantly reduce the selling price of renewable natural gas and decrease greenhouse gas emissions.
Review
Environmental Sciences
Md Nahid Pervez, Amir Mahboubi, Clarisse Uwineza, Tiziano Zarra, Vincenzo Belgiorno, Vincenzo Naddeo, Mohammad J. Taherzadeh
Summary: This review focuses on the recovery methods and technologies of volatile fatty acids (VFAs), with a special emphasis on membrane filtration. Filtration techniques such as nanofiltration and reverse osmosis have shown great potential in recovering VFAs. Factors such as operational parameters, membrane properties, and effluent characteristics are discussed in relation to the success of VFAs recovery.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Mengjia Tian, Feng Liu, Jiawen Guo, Wei Li, Mao Zhang, Xiang Li
Summary: This study investigated the effects of pH environment on the recovery of organic acid using potassium ferrate. The results showed that alkaline ferrate pretreatment significantly reduced the VSS of sludge and resulted in a higher accumulation of VFA during anaerobic digestion, without the need for additional alkaline substances.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2022)
Article
Agronomy
Xiaohong Su, Jingbo Qu, Yan Huang, Wei Liu, Yong Sun
Summary: Reflux of biogas slurry is an effective way to reduce wastewater discharge. This study investigated the pretreatment of biogas slurry using microfiltration membrane and biochar adsorption. The results showed that the combination of 0.65 μm microfiltration and 7 g/L biochar had the best filtration and adsorption effects. The anaerobic co-digestion of the pretreated reflux fluid and corn stover resulted in advanced gas production and higher methane production.
Article
Environmental Sciences
Borja Lagoa-Costa, Christian Kennes, Maria C. Veiga
Summary: The study aimed to investigate the microbial dynamics in response to a gradual change in feedstock composition during co-digestion of cheese whey and brewery wastewater, as well as its impact on PHA production. The results showed that the microbial community changed as the feedstock ratio gradually increased, leading to alterations in VFA profile and monomeric composition of the biopolymer.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Chemistry, Physical
Hong Xiao, Dexin Fang, Yingjun Wang, Yinlong Xiao, Lin Luo, Zhang Cheng, Xiaohong Zhang, Hong Peng
Summary: The study showed that anaerobic co-digestion of Nymphoides peltatum with waste sludge can increase methane production, significantly accelerate digestion rate, and have a synergetic effect. High-throughput sequencing revealed that Bacteroidetes, Firmicutes, Methanosarcina, and Methanosaeta are beneficial for AD of NP.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Environmental Sciences
Yuqi Wu, Xiuping Yue, Aijuan Zhou, Xiulan Song, Bingqin Su, Fang Cao, Jianzhi Ding
Summary: Anaerobic fermentation (AF) with sodium hydroxide (NaOH) conditioning was used to achieve simultaneous recovery of short-chain fatty acids (SCFAs) and phosphorus (P) from waste activated sludge (WAS) and meat processing waste (MPW). The addition of NaOH improved the AF performance by inhibiting the degradation of long-chain fatty acids. Anaerovibrio and Aminobacterium were identified as the major genera in the lipid-rich AF system. The study also demonstrated successful recovery of P through vivianite crystallization method. Overall, this study provides a new approach for SCFAs and P recovery from WAS and MPW through AF with NaOH conditioning and vivianite crystallization.
Article
Environmental Sciences
Yuqi Wu, Zichuan Wu, Chunfan Yang, Xiuping Yue, Aijuan Zhou, Xiulan Song, Bingqin Su
Summary: This study aimed to extract orthophosphate (ortho-P) from lipid-rich waste AF liquor (AFL) by Mg/Al layered double hydroxides (Mg/Al LDHs) adsorption. Low carbonate level was found to be favorable for P extraction. Kinetics and mechanisms analysis indicated that the adsorption of P onto Mg/Al LDHs was a rapid physiochemical process.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Engineering, Environmental
Ziqi Zhang, Wenzong Liu, Qun Gao, Fang Huang, Yuanyuan Kang, Yusheng Pan, Gaoyang Luo, Xu Zhou, Lu Fan, Aijie Wang, Shu-Hong Gao
Summary: Wastewater treatment plants (WWTPs) play a crucial role in removing microplastics (MPs) from urban wastewater. However, there is currently a lack of reliable and efficient methods for extracting MPs, especially in organic-rich matrices such as sludge samples. In this study, a two-step digestion process was developed and optimized, allowing for over 90% extraction efficiency of MPs from sludge samples. The recommended dosage of digestion reagents was found to be 100 ml 30% H2O2 + 100 ml 1 M HNO3 for samples with mixed liquid volatile suspended solids (MLVSS) levels lower than approximately 0.43 g. This study also examined the characteristics of MPs in two WWTPs in Shenzhen, revealing high concentrations of MPs in influent, effluent, and dewatered sludge, with rayon and polyester being the dominant polymers.
Article
Green & Sustainable Science & Technology
Xu Kang, Yu Liu, Wenzong Liu, Ling Wang, Chaolin Li
Summary: This study investigated the effect of organic load on fermentation and biogas production in a bioelectrolysis-assisted AD reactor. The results showed that the integrated system had a stronger tolerance to organic loads than the traditional anaerobic system. Under a high organic load, the methanogenic rate, total methane yield, and SS removal rate significantly increased.
Review
Engineering, Environmental
Zhang-Wei He, Fei Wang, Zheng-Shuo Zou, Cong-Cong Tang, Ai-Juan Zhou, Wenzong Liu, Yong-Xiang Ren, Zhihua Li, Aijie Wang
Summary: Waste activated sludge (WAS) is a major by-product of wastewater treatment plants, and anaerobic digestion (AD) is a promising technology for resource recovery and sludge stabilization. However, the presence of refractory organics, specifically humic acid (HA), in WAS can affect AD. This review summarizes recent advances in understanding the fates, roles, and mitigation strategies of HA in AD of WAS, and highlights the need for further research on the dynamic evolution and transformation pathways of HA, as well as the multi-functional roles it plays in electron transfer pathways and microbial communities.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Environmental Sciences
Cuicui Wang, Jierong Zheng, Sufang Wang, Aijuan Zhou, Xin Kong, Bowei Zhao, Houfen Li, Xiuping Yue
Summary: The degradation of alkylphenol pollutants was investigated using microbial electrolysis cells (MECs) due to their harmful effects. The study found that MECs could effectively degrade nonylphenol and 4-tert-octylphenol, with degradation rates higher than that of the group without applied voltage. GC-MS analysis revealed the degradation pathways of both pollutants and microbial community analysis identified the key bacteria involved in the degradation process. The MEC system was shown to be efficient, environmentally friendly, and have broad application prospects.
Article
Environmental Sciences
Xiangyu Gao, Jiaqi Yang, Wenzong Liu, Xiqi Li, Wenzhe Zhang, Aijie Wang
Summary: The loss and negative impacts of nitrogen from fertilized soils remain a global challenge in agriculture. Alkaline biochar, as a soil amendment with improved adsorption capacities, shows promising effects in mitigating nitrogen loss and improving nitrogen availability. This study investigated the effects of alkaline biochar on nitrogen mitigation, the interactions among mixed soils, and the potential use of a urea inhibitor in reducing nitrogen loss.
ENVIRONMENTAL RESEARCH
(2023)
Article
Chemistry, Physical
Qian Wei, Houfen Li, Yang Guo, Cong Gao, Rui Li, Aijuan Zhou, Sufang Wang, Xiuping Yue
Summary: The paper investigated the NO3- removal efficiency of nZVI nanoparticles deposited on the g-C3N4/rGO composite under visible light irradiation. The results showed that the g-C3N4/rGO/nZVI material achieved 100% of NO3- reduction efficiency in 60 min. The TN removal efficiency of g-C3N4/rGO/nZVI was 82.8%, superior to nZVI and g-C3N4/nZVI.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Environmental Sciences
Xiao Zhang, Bowei Zhao, Rui Li, Ying Cui, Fei Xie, Aijuan Zhou, Jinping Li, Xiuping Yue
Summary: The influence of hydraulic retention time (HRT) on the granulation process, methane-producing capacity, microbial community structure, and pollutant removal efficiency of an up-flow anaerobic sludge blanket (UASB) with simulated municipal wastewater was investigated. The results showed that even at low COD concentrations, the proportion of granular sludge in the UASB was high, and the COD removal efficiency was good. Shortening the HRT resulted in dense granular sludge and reduced the load of subsequent treatment processes.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Chemistry, Multidisciplinary
Zhixuan Cui, Zhihong Liu, Yaxin Fan, Zhang-Wei He, Wenzong Liu, Xiuping Yue, Aijuan Zhou
Summary: In this study, a novel coupling strategy of Fe(II)-activated PDS pretreatment with SRB was explored to enhance methane yield from WAS during AD. Results showed that Fe(II)_PDS + SRB and ZVI_PDS + SRB had a similar methane yield, which was higher than other groups. The hydrolysis rate constant in Fe(II)_PDS + SRB was also higher than that in ZVI_PDS + SRB. The concentration of SCFAs and the ultimate utilization efficiency of SCFAs were higher in the Fe(II)_PDS + SRB group, providing a more ideal substrate for methanogens. Furthermore, the study revealed the intrinsic interaction of functional microbial consortia in the Fe(II)_PDS + SRB group.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Biotechnology & Applied Microbiology
Xiangyu Gao, Wenzong Liu, Xiqi Li, Wenzhe Zhang, Shenglin Bu, Aijie Wang
Summary: The authors prepared a new straw decomposition agent using three fungi (Trichoderma viride, Penicillium, and Phanerochaete chrysosporium burdsall) for lignin, cellulose, and hemicellulose decomposition. The highest efficiency was achieved when the three fungi were mixed in a mass ratio of 1:1:1, resulting in a straw decomposition rate of 45.2% in a 10-day continuous reaction. The depth of straw in soil and the application of composite fertilizer were found to play important roles in straw decomposition. Nutrient release from straw decomposition was observed, with maximum release rates of 48.3% for N, 60.3% for P, and 72.1% for K after 90 days of reaction. The novel straw decomposition agent showed comparable performance to commercial straw decomposition agents, indicating its great potential in practical applications.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2023)
Article
Green & Sustainable Science & Technology
Qiandi Wang, Xiqi Li, Wenzong Liu, Siyuan Zhai, Qiongying Xu, Chang'an Huan, Shichen Nie, Qinghua Ouyang, Hongcheng Wang, Aijie Wang
Summary: Carbon cycle regulation and GHG emission abatement in WWTPs can improve sustainability. However, external carbon sources used for nitrogen removal and waste sludge disposal aggravate the carbon footprint. In this study, carbon was recovered from primary sludge through acidogenic fermentation and used for denitrification in an industrial WWTP. The recovered carbon sources enhanced denitrification and contributed to GHG emission reduction.
ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY
(2023)
Article
Environmental Sciences
Qi Sun, Ying-Ke Fang, Wen-Zong Liu, Nan Xie, Heng Dong, Awoke Guadie, Ying Liu, Hao-Yi Cheng, Ai-Jie Wang
Summary: In recent years, biological sulfur (bio-S) has been used in sulfur autotrophic denitrification (SAD) with autotrophic Thiobacillus denitrificans and heterotrophic Stenotrophomonas maltophilia. The growth pattern of T.denitrificans and S.maltophilia showed a linear relationship between OD600 and CFU below certain thresholds. S.maltophilia's DsrA could produce sulfide as an alternative electron donor for T.denitrificans. The interaction of T.denitrificans and S.maltophilia reduced nitrite accumulation and improved denitrification efficiency.
ENVIRONMENTAL RESEARCH
(2023)
Article
Biotechnology & Applied Microbiology
Fang Cao, Xujiang Guo, Xiaoyun Yin, Zhixuan Cui, Shuli Liu, Aijuan Zhou
Summary: This study investigated the use of ferrous-iron (Fe(II))-activated sulfite to overcome the slow hydrolysis and low acid production efficiency of waste-activated sludge (WAS) in traditional anaerobic fermentation. The results showed that Fe(II)-activated sulfite significantly promoted the breakdown of extracellular polymers and the production of short-chain fatty acids (SCFAs). The highest concentration of SCFAs reached 7326.5 mg COD/L under the optimal dosage of Fe(II)/S(IV). The analysis also revealed that Fe(II)-activated sulfite had a synergistic effect on sludge cell rupture and extracellular polymer stripping, generating key radicals such as SO4- and OH.
FERMENTATION-BASEL
(2023)