Article
Environmental Sciences
Yijie Zhong, Junguo He, Fei Wu, Pengfei Zhang, Xiang Zou, Xinlei Pan, Jie Zhang
Summary: The addition of magnetite with smaller particle sizes during the anaerobic digestion of waste-activated sludge after thermal hydrolysis pretreatment increased methane production and enzyme activities, while influencing the establishment of direct interspecies electron transfer.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Green & Sustainable Science & Technology
Guangyi Zhang, Yinghao Shi, Wanxue Chen, Ming Dou, Zisheng Zhao, Xiaowei Wang, Tingting Zhang
Summary: The study proposed a new strategy to minimize the inhibition of CaO2 reaction residues by adding zero-valent iron (ZVI) to the pretreated sludge, which significantly improved methane production and sludge reduction. Mechanism analysis indicated that ZVI enhanced the activities of the electron transport system (ETS) and coenzyme F420 to reduce the inhibition to methanogens caused by high concentrations of ammonia. Microbial community analysis also showed that ZVI effectively improved the abundance of hydrogenotrophic methanogens.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Biotechnology & Applied Microbiology
Hui Zhang, Junhui Wu
Summary: Response surface methodology was used to optimize the aqueous ammonia pretreatment and enzymatic hydrolysis of corn cob powder using self-produced cellulases from Aspergillus niger HQ-1. The study identified the optimal conditions for pretreatment and enzymatic hydrolysis, resulting in high cellulose and hemicellulose recovery rates.
BIOCHEMICAL ENGINEERING JOURNAL
(2021)
Article
Environmental Sciences
Jialin Liang, Xiaojian Liao, Maoyou Ye, Zhijie Guan, Zhihua Mo, Xian Yang, Shaosong Huang, Shuiyu Sun
Summary: The study compared the activation of peroxymonosulfate (PMS) by zero-valent iron (Fe-0) and zero-valent aluminum (Al-0) for waste activated sludge (WAS) conditioning. Fe-0/PMS treatment showed superior dewaterability of WAS and reduced operational costs compared to Al-0/PMS treatment. The study proposes a novel perspective for selecting an optimal PMS activator in sludge treatment to alleviate environmental risks.
Article
Agricultural Engineering
Jue Wang, Yuan Xu, Baoying Tang, Minxia Zeng, Zhiquan Liang, Cuifeng Jiang, Jianghai Lin, Wenjuan Xiao, Zehuan Liu
Summary: In this study, sugarcane bagasse was treated with a mixture of NaOH and ammonia for pretreatment, enzymatic hydrolysis and fermentation. By optimizing the parameters with response surface methodology, the highest total reducing sugar concentration and total reducing sugar yield were achieved, leading to TRSC of 16.23 g/L and TRSY of 0.46 g/g.
INDUSTRIAL CROPS AND PRODUCTS
(2021)
Article
Engineering, Chemical
Xianke Sun, Yanxin Qin, Wen Zhou
Summary: This paper studied the degradation of amoxicillin by ultrasound-zero valent iron activated sodium persulfate and optimized the best degradation conditions. The research found that ultrasonic power, sulfate concentration, and zero-valent iron dosage have significant impacts on the removal efficiency of amoxicillin.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Agricultural Engineering
Shichao Zheng, Fei Yang, Wenli Huang, Zhongfang Lei, Zhenya Zhang, Weiwei Huang
Summary: The combined effect of ZVI and magnetite on semi-dry anaerobic digestion of swine manure was studied. The results showed that both ZVI and magnetite increased methane production by altering the metabolism pathways. ZVI promoted interspecies hydrogen transfer, while magnetite accelerated organic hydrolysis and established direct interspecies electron transfer.
BIORESOURCE TECHNOLOGY
(2022)
Article
Agricultural Engineering
Shereena P. Joy, Chandraraj Krishnan
Summary: The study demonstrates that pretreatment with ammoniacal glycerol can significantly improve saccharification efficiency and ethanol yield from sorghum biomass, benefiting both biodiesel and bioethanol industries.
INDUSTRIAL CROPS AND PRODUCTS
(2022)
Article
Engineering, Environmental
Gaofeng Zhou, Runyu Zhou, Yiqing Liu, Li Zhang, Linyue Zhang, Yongsheng Fu
Summary: A novel heterogeneous peracetic acid (PAA)-based advanced oxidation process (AOP), ZVCo/PAA, was developed to remove sulfamethoxazole (SMX). The results showed that ZVCo/PAA could remove about 99% of SMX in 5 minutes under neutral condition. The characterization results of ZVCo before and after reaction revealed the corrosion and activation mechanism of ZVCo. Radical scavenging experiments indicated that organic radicals were the dominant reactive species for SMX degradation. SMX could be degraded well at a wide pH range, and ZVCo showed good stability and reusability.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Agricultural Engineering
Xiaoxiao Jiang, Rui Zhai, Haixiang Li, Chen Li, Qiufeng Deng, Mingjie Jin
Summary: DLCA(sa) pretreatment is a low temperature and densification method for lignocellulosic biomass, which demonstrates high efficiency. This study systematically investigated the effects of temperature, acid loading, and time on the hydrolysis of xylan, cellulose, and lignin during DLCA(sa) pretreatment. It was shown that DLCA(sa) pretreatment can effectively solubilize xylan under mild conditions and a mathematical model based on xylan hydrolytic kinetics was proposed to predict enzymatic hydrolysis. The kinetic model suggested that mechanical densification facilitates the penetration of acid into the biomass matrix, increasing the accessibility of xylan to acid catalysis.
BIORESOURCE TECHNOLOGY
(2023)
Article
Engineering, Environmental
Qingxia Li, Xin Kong, Yuxin Chen, Jianan Niu, Jia Jing, Jin Yuan, Yifeng Zhang
Summary: This study investigates how to enhance methane production from food waste after hydrothermal pretreatment. The results demonstrate a significant increase in methane yield when zero-valent iron and magnetite are used together, and high organic loading is favorable for methane production. Microbial diversity analysis further reveals the dominant pathways and metabolic processes involved in methane generation.
Article
Environmental Sciences
Zhengqin Shi, Ping Zhang, Xiaohan Li, Yijie Zheng, Juanxi Huang, Yaxuan Wang, Xiatiao Luo, Gaosheng Zhang, Tangfu Xiao, Jianyou Long, Huosheng Li
Summary: This study investigated the performance and mechanisms of sulfidized zero-valent manganese (SZVMn) for removing thallium (Tl) from wastewater. The results showed that liquid nitrogen modified SZVMn (LSZVMn) had more interior channels and pores than SZVMn, leading to improved adsorption of Tl(I). LSZVMn demonstrated effectiveness and robustness in Tl(I) removal in the presence of co-existing ions up to 0.1 M. The mechanism of Tl(I) removal with SZVMn involved sulfidation-induced precipitation, manganese reduction, surface complexation, and electrostatic attraction.
Article
Environmental Sciences
Kejia Zhang, Jing Deng, Yijing Chen, Chengcheng Xu, Cheng Ye, Xiao Ling, Xueyan Li
Summary: The study introduced ascorbic acid in the ZVC/air process to efficiently activate molecular oxygen and generate reactive oxygen species for the destruction of ciprofloxacin. The optimal dosages of nZVC and AA were determined to be 0.2 g/L and 1 mM, respectively, allowing the process to operate effectively in a broad pH range of 3.0-7.0.
Article
Chemistry, Physical
An Guo, Li Hu, Yumei Peng, Yi Wang, Yan Long, Jinsong Fu, Guangyin Fan
Summary: An economical, simple, and efficient steam pretreatment-mediated strategy using nitric acid vapor was introduced to adjust the surface chemistry and textural structure of carbon nanotubes, facilitating the uniform deposition of Ru nanoclusters for enhanced hydrogen production from ammonia borane hydrolysis. Ru nanoclusters with high dispersion (1.71 nm in diameter) were formed on functionalized carbon nanotubes, leading to significantly improved catalytic activity in hydrogen generation from ammonia borane hydrolysis. This strategy provides an efficient approach for preparing various carbon-supported metal catalysts with promising catalytic applications.
APPLIED SURFACE SCIENCE
(2022)
Article
Environmental Sciences
Di Zhang, Shengkun Dong, Aihong Zhang, Li Chen, Zhenxun Yu, Qi Wang, Wenhai Chu
Summary: ZVI acted as a catalyst to promote the hydrolysis of HANs, reducing their cytotoxicity and genotoxicity. The degradation rates of HANs were significantly affected by initial pH, ZVI doses, and initial HAN concentration. ZVI induced the transformation of HANs to less toxic compounds, providing a theoretical foundation for future HAN control efforts.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Engineering, Environmental
Yi-Kun Geng, Yan Zhou
Summary: The addition of Fe3+ in the thermal hydrolysis pretreatment of waste activated sludge was found to improve solubilization and reduce refractory residuals, leading to an increase in methane production. This simple and economical strategy provides a way to enhance energy recovery from the THP-AD system.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Engineering, Environmental
Jialin Liang, Yan Zhou
Summary: The article discusses the application of iron-based AOP technology in sludge dewatering processes, summarizes the factors affecting sludge dewaterability, and analyzes the mechanisms of iron-based AOPs to improve dewatering processes.
Article
Engineering, Environmental
Liang Zhang, Xianzhe Gong, Ronghua Xu, Kun Guo, Li Wang, Yan Zhou
Summary: This study investigates the impact of thermophilic conditions on the assembly of microbial communities and their effects on anaerobic digestion (AD) ecosystem function. The inocula from full-scale systems showed greater resilience to thermophilic environment and demonstrated higher methane production. Deterministic processes played a dominant role in community assembly, but stochastic processes were more influential in dysfunctional AD ecosystems. The thermophilic environment exerted strong selective pressure on microbial network structures.
Article
Agricultural Engineering
Shenbin Cao, Rui Du, Yan Zhou
Summary: This study demonstrates that the inhibitory effects of recalcitrant organics (RO) can be alleviated and the high nitrate issue in the effluent of the Two-stage Partial nitritation/Anammox (PN/A) process can be addressed by co-treating with municipal wastewater (MW). Furthermore, microbial analysis reveals the key microbial species responsible for ammonium oxidation and nitrogen removal in the PN/A system.
BIORESOURCE TECHNOLOGY
(2022)
Article
Engineering, Environmental
Yifeng Xu, Ning Wang, Lai Peng, Shengjun Li, Chuanzhou Liang, Kang Song, Shaoxian Song, Yan Zhou
Summary: Limited studies have investigated the biodegradation of atenolol during the sidestream partial nitritation (PN) process. This study found that the presence of free nitrous acid (FNA) inhibited atenolol removal, with higher FNA levels resulting in lower biodegradation efficiencies. Ammonia-oxidizing bacteria (AOB)-induced metabolism was predominant in all conditions, but its activity was decreased in the presence of FNA. The study also identified new products and pathways related to different metabolic types and FNA levels.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Environmental Sciences
Dan Wu, Zelong Zhao, Liang Zhang, Li Wang, Yan Zhou
Summary: This study used a genome-centric metagenomic approach to investigate the shift in microbial community structures and functional genes of purple non-sulfur bacteria (PNSB) under light and dark conditions. The results showed that Rhodopseudomonas palustris promoted complex metabolic processes and interactions for carbon, nitrogen, and phosphorus conversions under light, while Burkholderia contaminans was identified as a potential organism for simultaneous carbon, nitrogen, and phosphorus removal.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Agricultural Engineering
Liang Zhang, Xianzhe Gong, Zhiyi Chen, Yan Zhou
Summary: This study elucidated the ecological roles and interactions of microbial communities in thermophilic THP-AD reactors. It was found that Fir-micutes dominated the enriched microbial community, and methane production was primarily mediated by Methanosarcina and Methanothermobacter. The accumulation of propionate could be attributed to weak propionate-oxidizing activity or its absence.
BIORESOURCE TECHNOLOGY
(2022)
Article
Engineering, Environmental
Jingshu Wang, Jinhui Jeanne Huang, Yan Zhou, Yuan Liao, Song Li, Beichen Zhang, Shiteng Feng
Summary: This study demonstrated the use of carbon-coated zerovalent iron (Fe-0@C) as an electron donor to enhance autotrophic denitrification and simultaneous removal of nitrogen and phosphorus. The carbon shell played a critical role in preventing direct contact between Fe-0 and phosphorus and nitrate, maintaining Fe-0 activity. Phosphorus removal indirectly boosted H-2 generation and promoted bio-denitrification, leading to improved removal of both nitrogen and phosphorus.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Agricultural Engineering
Liang Zhang, Xiuping Wang, Yun Chen, Baorui Zhang, Hui Xu, Chenchen Li, Yan Zhou
Summary: In this study, the production of medium-chain fatty acids (MCFA) from mixed sludge without additional electron donors (EDs) was investigated. The anaerobic fermentation of mixed sludge without thermal hydrolysis process (THP) pretreatment generated 0.5 g COD/L of MCFAs with the in situ generated ethanol serving as the EDs. The addition of ethanol improved MCFA yield and caproiciproducens was the dominant chain-elongating bacteria.
BIORESOURCE TECHNOLOGY
(2023)
Article
Environmental Sciences
Pengfei Zhang, Yan Zhou, Xinlei Pan, Junguo He, Xiang Zou, Yijie Zhong, Jie Zhang, Qiupeng Cai
Summary: In this study, the combination of lysozyme and sodium citrate pretreatment was used to stabilize aluminum and enhance the production of VFAs in anaerobic fermentation of aluminum-rich waste activated sludge (WAS). The results showed that citrate efficiently complexed and stabilized aluminum, alleviating its inhibition on lysozymes and other extracellular hydro lases. The lysozyme, protease, and alpha-glucosidase activities increased by 1.86, 1.72, and 1.15 times, respectively, after the pretreatment. The total VFAs produced from the Al-rich WAS after six-day anaerobic fermentation following the lysozyme and sodium citrate pretreatment were 7.3 times higher than the control group. This study presents a novel approach to enhance VFA production in anaerobic fermentation and mitigate the risk of aluminum pollution from aluminum-rich WAS.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Hui Xu, Liang Zhang, Chunhong Yao, Bo Yang, Yan Zhou
Summary: This study developed a core-shell structured Fe@C composite to demonstrate its long-term feasibility for enhancing azo dye biodegradation, compared to a mixture of NZVI and carbon powder (Fe+C). The results showed that Fe@C had better performance, durability, and stability than Fe+C, possibly due to the carbon layer's ability to form a stable buffer to regulate NZVI dissolution. The microbial community analysis revealed that Fe@C promoted the growth of azo dye degraders, and metatranscriptomic analysis further revealed the substantial stimulation of genes involved in the extracellular degradation of azo dye by Fe@C. This study provides novel insights into the bioaugmentation of Fe@C for refractory wastewater treatment.
Article
Engineering, Environmental
Qi Li, Yifeng Xu, Chuanzhou Liang, Lai Peng, Yan Zhou
Summary: This study investigated the nitrogen transformation pathways and nitrous oxide (N2O) reduction potential of an algal-bacterial consortium in different types of reactors. The results showed that the algal-bacterial consortium had superior efficiency in removing ammonium, achieving a removal rate of 7.34 mg N g MLSS-1 h-1 in the open reactor with glucose. The consortium achieved enhanced total nitrogen removal through mixotrophic algal assimilation and bacterial denitrification. Additionally, the consortium significantly reduced N2O production through autotrophic and mixotrophic pathways, thanks to the synergistic effects between algae and bacteria.
Article
Environmental Sciences
Yi-Kun Geng, Jun Gu, Xiaoyuan Zhang, Zhuan Khai Lim, Yishuai Jiang, Meng Zhang, Yan Zhou, Yu Liu
Summary: This study developed an innovative A-B process for carbon-neutral wastewater treatment by combining an anaerobic biofilm reactor (AnBR) as the A stage for energy recovery and a step-feed membrane bioreactor (MBR) as the B stage for mainstream deammonification. A multi-parameter control-based operation strategy was developed to address the challenge of selectively retaining ammonia-oxidizing bacteria (AOB) over nitrite oxidizing bacteria (NOB). Results showed that this process configuration achieved high removal rates of COD, ammonium-N, and total nitrogen, while promoting the growth and enrichment of anammox bacteria.
Article
Environmental Sciences
Rui Wang, Zijing An, Lu Fan, Yan Zhou, Xiaomei Su, Junjie Zhu, Qian Zhang, Chongjun Chen, Hongjun Lin, Faqian Sun
Summary: Quorum quenching (QQ) is a novel technique for controlling biofouling in membrane bioreactors (MBRs) by disrupting quorum sensing (QS) and inhibiting biofilm formation. This study evaluated the effectiveness of the QQ strain Brucella sp. ZJ1, encapsulated in alginate beads, in mitigating biofouling. The results showed that MBR with QQ beads extended operation time by 2-3 times without affecting pollutant degradation, and these beads maintained approximately 50% QQ activity even after 50 days of operation.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Engineering, Environmental
Wangwang Yan, Mengsha Song, Yan Zhou
Summary: This study developed a hierarchical scheme to identify the key factors contributing to the elevation of free PFOA during the thermal hydrolysis pretreatment (THP) process. The relative abundance of PFOA in the liquid phase increased during THP, while changes in pH, zeta potential, ionic condition, and specific surface area had negligible impact on PFOA redistribution. The study provides valuable insights into how sludge transformations regulate the distribution of PFCs and guide the selection of treatment processes.
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.