Article
Engineering, Environmental
Fangzhai Zhang, Yongzhen Peng, Zhong Wang, Hao Jiang, Shang Ren, Jingang Qiu, Liang Zhang
Summary: The PNFA system achieved efficient nitrogen removal in treating landfill leachate and waste activated sludge, reducing the need for external carbon sources and energy consumption while also decreasing CO2 emissions.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Environmental Sciences
Xiaofei Gong, Feng Hou, Hongtao Pang, Yuanyuan Guo, Qiong Zhang, Xiyao Li, Liang Zhang, Yongzhen Peng
Summary: This study achieved stable and efficient nitrogen removal through a zero-external carbon Partial Nitritation/Anammox combined with in-situ sludge Fermentation-Denitrification process under decreased temperatures. The findings show the resilience of anammox to lower temperatures and highlight the importance of sludge reduction and organic recovery for enhanced denitrification.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Environmental Sciences
Boqun Ye, Jiamin Zhang, Yintong Zhou, Mengge Tang, Fengyuan You, Xiaoming Li, Qi Yang, Dongbo Wang, Xuran Liu, Abing Duan, Junwu Liu
Summary: A combination of FNA and Ca(ClO)2 significantly improved sludge fermentation performance, boosting hydrogen generation by 39.97% to 76.20%. Mechanism analysis showed that the combined treatment disrupted sludge structure and cell membrane permeability, releasing more organic substrates and enhancing biodegradability. This study provides a unique strategy for sludge pretreatment, expanding the use of Ca(ClO)2 and FNA in anaerobic fermentation, with implications for sludge disposal and energy recovery.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Agricultural Engineering
Qiang He, Jinjin Liu, Yongzhen Peng, Xiyao Li, Qiong Zhang
Summary: The use of sludge alkaline fermentation promoted nitrogen removal and enrichment of anammox bacteria in wastewater with low carbon-to-nitrogen (C/N) ratio. This system saves energy and reduces consumption significantly.
BIORESOURCE TECHNOLOGY
(2022)
Article
Engineering, Environmental
A. Kuokkanen, K. Blomberg, A. Mikola, M. Heinonen
Summary: The spontaneous and significant increase in NO2- levels in activated sludge processes can lead to high nitrous oxide emissions, underlining the importance of continuous monitoring and control measures for N2O emissions.
WATER SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Environmental
Yuqi Wu, Xiulan Song, Yuhong Zhang, Yaohui Liu, Bingqin Su, Yiwen Zhou
Summary: Free nitrous acid (FNA) pretreatment and alkyl polyglucoside (APG) addition are environmentally-friendly methods for enhancing waste activated sludge (WAS) anaerobic fermentation (AF) performances and reducing the cost of polyhydroxyalkanoates (PHAs) synthesis. Through investigating the effects of FNA + APG treatment, key enzyme activities, and microbial community variation, optimal fermentation conditions were identified and the performance of PHAs synthesis using SCFAs from the AF system was evaluated. Results showed that the combination of 0.653 mg/L FNA and 0.075 g/g VSS APG treatment achieved the maximum total SCFAs yield of 324.94 mg COD/g VSS at day 5 of AF, promoting solubilization, hydrolysis, and acidogenesis while inhibiting methanogenesis. Furthermore, the dominant genera in the FNA + APG reactor were SCFA producers, Enterococcus and Clostridium. Batch-mode PHAs synthesis using AF liquor as a carbon source resulted in a maximum PHA yield of 44.44% of biomass (w/w) after five operation periods.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Environmental Sciences
Zhihong Liu, Aijuan Zhou, Sufang Wang, Shuanglan Cheng, Xiaoyun Yin, Xiuping Yue
Summary: The study explored the feasibility of utilizing free nitrous acid pretreatment combined with quorum sensing to enhance hydrogen recovery from waste activated sludge via electro-fermentation. The results showed that the combination of quorum sensing and free nitrous acid enabled the highest hydrogen yield and current, indicating a potential cooperative relationship among anaerobic fermentation bacteria, electroactive bacteria, and homoacetogens in the electro-fermentation system.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Agricultural Engineering
Xiaodi Li, Bo Wang, Yuqing Ma, Tan Jiang, Yongzhen Peng
Summary: This study investigated the reduction of nitrate in waste activated sludge fermentation and found that nitrate promoted the release of organic matter in sludge and enhanced its biodegradability. The destruction of volatile suspended solids was increased significantly in the presence of nitrate. Nitrate reduction also promoted sludge hydrolysis and acetogenesis, but slightly inhibited acidogenesis. This study provides a feasible method to address the overabundance of waste activated sludge and the lack of carbon sources in the denitrification process.
BIORESOURCE TECHNOLOGY
(2023)
Article
Green & Sustainable Science & Technology
Qizi Fu, Dongbo Wang, Xiaoming Li, Qi Yang, Qiuxiang Xu, Bing-Jie Ni, Qilin Wang, Xuran Liu
Summary: Hydrogen production from waste activated sludge is a promising technology to recover energy from wastewater treatment plants, but there are challenges such as low organics utilization and rapid hydrogen consumption. Further research and solutions are needed to address these challenges and make the technology more feasible.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Engineering, Environmental
Xianli Yang, Jingnan Yang, Xuran Liu, Qing Wang, Dongke Liu, Dongbo Wang
Summary: The widespread use of pharmaceuticals has raised concerns about their potential environmental effects. Previous studies have shown that most of the pharmaceuticals investigated had harmful effects on wastewater or sludge treatment. However, this study found that carbamazepine at environmentally relevant levels increased hydrogen production from anaerobic fermentation of waste activated sludge.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Green & Sustainable Science & Technology
Dorota Szypulska, Stanislaw Miodonski, Kamil Janiak, Mateusz Muszynski-Huhajlo, Bartosz Zieba, Grzegorz Cema
Summary: The study found that higher concentrations of FNA than previously reported can release more organic matter, which may be beneficial for wastewater treatment plants. The demand for organic compounds for denitrification may constitute up to 86% of total released SCOD and must be considered. Moreover, increasing FNA concentrations above 6.4 mgHNO(2)-N/L did not benefit the growth of SBMP anymore.
Article
Agricultural Engineering
E. Statiris, T. Dimopoulos, N. Petalas, C. Noutsopoulos, D. Mamais, S. Malamis
Summary: This study examined the short and long-term effects of different levels of free ammonia (FA) and free nitrous acid (FNA) on the treatment of sludge reject water and municipal wastewater. Results showed that in acclimatized biomass, the transition from nitrification to nitritation occurred at FA levels of 10-20 mgNH3-N/L, while the ammonia uptake rate (AUR) in the SBR unit was not inhibited at FA levels up to 65 mgNH3-N/L. Short-term exposure to FNA showed that AUR inhibition could be more than 50% for FNA concentrations > 10 μgHNO(2)-N/L.
BIORESOURCE TECHNOLOGY
(2022)
Article
Environmental Sciences
Yun Wang, Wei Wei, Xiaohu Dai, Bing-Jie Ni
Summary: The study proposed a green method using corncob ash to enhance hydrogen production during anaerobic fermentation of waste activated sludge. Corncob ash dosage positively correlated with hydrogen production, reaching up to 46.8 +/- 1.0 mL/g VS. Mechanistic studies showed benefits in solubilization, hydrolysis, and acetogenesis processes.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Jingnan Yang, Abing Duan, Dongbo Wang, Xianli Yang, Xuran Liu, Guojing Yang, Qi Yang
Summary: Hydrogen production from waste-activated sludge anaerobic fermentation is an effective method of resource recovery. However, the presence of diclofenac, a widely used anti-inflammatory drug, inhibits hydrogen production by binding to the active sites of hydrogenase, which leads to the inhibition of acetogenesis and acidogenesis processes that are responsible for hydrogen production.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Environmental Sciences
Alice Muhorakeye, Roent Dune Cayetano, Naresh Kumar, Jungsu Park, Ashutosh Kumar Pandey, Sang-Hyoun Kim
Summary: Polyhydroxybutyrate (PHB), a natural polyester, was synthesized using volatile fatty acids (VFAs) as a substrate. Optimization tests were conducted to improve the biodegradability and hydrolysis of waste activated sludge. The results showed that SDBS pretreatment and pH adjustment during continuous acidogenesis yielded stable VFA conversion and high PHB production.
Article
Engineering, Environmental
Rong-Gui Zhu, Chang-Gui Pan, Feng-Jiao Peng, Chao-Yang Zhou, Jun-Jie Hu, Kefu Yu
Summary: This comprehensive survey investigated the occurrence, bioaccumulation, and trophic magnification of parabens and their metabolite 4-HB in a marine food web. Results showed that parabens were the predominant pollutants in marine organisms, with significant bioaccumulation from sediments. The estimated trophic magnification factor indicated biomagnification for MeP and trophic dilution for 4-HB. Overall, the risks for humans consuming marine organisms were found to be low.
Article
Engineering, Environmental
Andres F. Torres-Franco, Deborah Leroy-Freitas, Cristina Martinez-Fraile, Elisa Rodriguez, Pedro A. Garcia-Encina, Raul Munoz
Summary: Anaerobic and microalgae-based technologies have emerged as sustainable alternatives for municipal wastewater treatment. However, the presence of viruses in the treated wastewater is a major concern for reuse applications. This study assessed the ability of these technologies to reduce viruses during secondary wastewater treatment. The results showed that all technologies were effective in reducing the concentration of viruses, with microalgae-based treatment exhibiting the highest potential for reducing the disinfection requirements of treated wastewater.
Article
Engineering, Environmental
Young Gwang Kim, Sae Yun Kwon, Spencer J. Washburn, Scott C. Brooks, Ji Won Yoon, Lucien Besnard
Summary: The study uses Hg isotope ratios to identify the sources and exposure pathways of mercury in bivalves, finding that dissolved Hg phases in the water column are the primary source and exposure pathway to bivalves. This provides new insights into using bivalves as bioindicators for sediment quality monitoring.
Article
Engineering, Environmental
Hui Geng, Ying Xu, Rui Liu, Dianhai Yang, Xiaohu Dai
Summary: This study investigates the effect of cation exchange resin (CER) on the sequential recovery of hydrogen and methane from anaerobic digestion (AD) and the corresponding mechanisms. The results show that CER can simultaneously enhance the production of hydrogen and methane by promoting the solubilisation, hydrolysis, and acidification of organic matter. Additionally, CER facilitates effective contact between bacteria and organic particulates and reduces the energy barrier for mass transfer during methane production. The study also reveals changes in the microbial community structure and metagenomics during the AD process.
Article
Engineering, Environmental
Xiaojing Lin, Zhan Jin, Shunfeng Jiang, Zhiquan Wang, Suqing Wu, Ke Bei, Min Zhao, Xiangyong Zheng
Summary: Dehumidification combined with addition of absorbent resin supplement (ARS) was used to achieve rapid evaporation of non-pretreated urine, resulting in high water evaporation efficiency and nutrient recovery.
Article
Engineering, Environmental
Yangli Che, Chaoran Lin, Shen Li, Jiao Liu, Longhai Zhu, Shilei Yu, Nan Wang, Haoshuai Li, Mutai Bao, Yang Zhou, Tonghao Si, Rui Bao
Summary: Hydrodynamic processes play a crucial role in the transmission of sediments, microbial assembly, and organic carbon redistribution in the ocean. Through experiments and analysis, we found that hydrodynamics shape the assembly of microbial communities and control the redistribution of different sourced organic carbon, thereby influencing microbial-mediated biogeochemical transformation.
Article
Engineering, Environmental
Chao Chen, Yu Yang, Nigel J. D. Graham, Zhenyu Li, Xingtao Yang, Zhining Wang, Nadia Farhat, Johannes S. Vrouwenvelder, Li -an Hou
Summary: The fouling of seawater reverse osmosis membranes is a persistent challenge in desalination. This study monitored the operational performance of a desalination plant for 7 years and the fouling development in different areas of membrane modules. The findings showed that operational performance declined over time and fouling mainly occurred at the feed side of the modules, with the highest microbial diversity. Keystone species like Chloroflexi and Planctomycetes played an important role in maintaining community structure and biofilm maturation. Polysaccharides, soluble microbial products, marine humic acid-like substances, and inorganic substances contributed to fouling. Overall, biofouling had a significant impact on membrane fouling after 7 years of operation.
Article
Engineering, Environmental
Dan Li, Jieyi Sun, Yibo Fu, Wentao Hong, Heli Wang, Qian Yang, Junhong Wu, Sen Yang, Jianhui Xu, Yunfei Zhang, Yirong Deng, Yin Zhong, Ping'an Peng
Summary: Sulfidation-oxidation treatment of magnetite (Fe3O4) enhances the production of dark center dot OH, which can efficiently degrade dissolved organic matter (DOM) and accelerate carbon cycling.
Article
Engineering, Environmental
Cheng Yu, Kaijun Wang, Kaiyuan Zhang, Ruiyang Liu, Pingping Zheng
Summary: This study implemented a microaerobic-aerobic configuration in a full-scale municipal wastewater treatment facility and investigated the effects on sludge characteristics, pollutant removal, microbial community, and granulation mechanisms. The results showed successful transition from flocculent-activated sludge to well-defined AGS after two months of operation. The primary pathways for pollutant removal were simultaneous nitrification, denitrification, and phosphorus removal. Moreover, the incorporation of internal separators induced shifts in the flow pattern, which promoted granulation.
Article
Engineering, Environmental
Zhe Zhang, Shaoyang Hu, Guangrong Sun, Wei Wang
Summary: Halogenated aromatic disinfection byproducts (DBPs), such as halogenated phenols, have garnered widespread attention due to their high toxicity and prevalence. This study reports on the analysis, occurrence, and cytotoxicity of a group of emerging halogenated aromatic DBPs, known as halogenated polyhydroxyphenols (HPPs), in drinking water.
Article
Engineering, Environmental
Shengyue Chen, Jinliang Huang, Peng Wang, Xi Tang, Zhenyu Zhang
Summary: Accurate prediction of river water quality is crucial for sustainable water management. This study introduces wavelet analysis and transfer learning techniques to assist LSTM modeling, proposing a newly coupled modeling approach that improves short-term prediction of river water quality.
Article
Engineering, Environmental
Bang Du, Xinmin Zhan, Piet N. L. Lens, Yifeng Zhang, Guangxue Wu
Summary: Efficient anaerobic digestion relies on the cooperation of different microorganisms with different metabolic pathways. This study investigated the effects of different operational modes and the addition of powdered activated carbon (PAC) on ethanol metabolic pathways. The results showed that the SBR mode and the presence of CO2 facilitated ethanol metabolism towards propionate production, while the CFR mode with extended solids retention time enriched Geobacter. Adjusting operational modes and PAC addition can modulate anaerobic ethanol metabolism and enrich Geobacter.
Article
Engineering, Environmental
Wanfa Wang, Si-Liang Li, Jun Zhong, Yuanbi Yi, Fujun Yue, Zenglei Han, Qixin Wu, Ding He, Cong-Qiang Liu
Summary: This study compares the carbon biogeochemical processes in karst and non-karst regions within large thermal stratified river-reservoir systems. The results demonstrate that karst reservoirs have a reduced potential for carbon emissions and highlight the importance of considering geologic settings to improve accuracy in regional and global CO2 emission estimates.
Article
Engineering, Environmental
Chunxia Jiang, Zelong Zhao, Dong Zhu, Xiong Pan, Yuyi Yang
Summary: This study analyzed the occurrence and distribution of antibiotic resistance genes (ARGs) in different environmental media of the Yangtze River using metagenomics. Core resistome dominated by multidrug resistance genes was found in all samples, while rare resistome dominated by various resistance genes was more prevalent in plasmids. Specific bacteria were identified as hosts for both core and rare resistomes, with high clinical concern ARGs found in the rare resistome. Particle-associated environment provided the most ideal conditions for resistome hosts. This study provided insights into the genetic locations of ARGs and the community assembly mechanisms of ARG hosts in freshwater environments.
Article
Engineering, Environmental
Yu Zhang, Yongtao He, Linchun Jia, Lei Xu, Zheng Wang, Yueling He, Ling Xiong, Xumeng Lin, Hong Chen, Gang Xue
Summary: By synergizing organic carbon source, thiosulfate, and zero-valent iron, efficient mixotrophic denitrification of oligotrophic secondary effluent can be achieved. Thiosulfate plays a vital role in promoting TN removal efficiency, while corrosion of Fe0 releases OH- to neutralize H+ from thiosulfate-driven denitrification, creating a suitable environment for denitrification. The coordination of thiosulfate and Fe0 maintains the dominance of Thiobacillus for denitrification.