Review
Environmental Sciences
Hui Zhong, Ning Hu, Qinghua Wang, Yucheng Chen, Lei Huang
Summary: Constructed wetland is a cost-effective and environmentally friendly technology for contaminated water treatment. However, substrate clogging is a major challenge in its long-term operation. This study reviews the effects of substrates on clogging and provides recommendations for substrates that can alleviate clogging, aiming to enhance the stable operation and technical level of constructed wetlands.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
S. Shrivastava, M. J. Stewardson, M. Arora
Summary: This study examines how the interaction between model organisms and fine sediment deposits affects hyporheic exchange flows in streambeds, finding that the modification of these flows depends on the overall reworking of the beds by organisms. The results demonstrate that the presence of organisms can lead to greater solute penetration depth, shorter residence times, and higher hyporheic exchange flux in stream ecosystems.
WATER RESOURCES RESEARCH
(2021)
Article
Agronomy
Chunping Yao, Lin Zhang, Pute Wu, Ying Liu, Yaohui Cai, Wei Zhou
Summary: This study investigated the clogging of porous ceramic emitters in subsurface drip irrigation systems by analyzing operational data and conducting flushing experiments. It found that clogging was primarily caused by substances precipitating at the emitter inlet and affecting water flow inside the micropores. Flushing with acid water for 15 minutes at a pressure of 100 kPa was recommended to minimize clogging.
AGRICULTURAL WATER MANAGEMENT
(2021)
Article
Biotechnology & Applied Microbiology
Megan Meinel, James Wang, Evan Cox, Phil Dennis, Cesar Torres, Rosa Krajmalnik-Brown
Summary: The influence of electrokinetic-enhanced bioremediation (EK-BIO) on subsurface microbial communities was investigated at a field-scale demonstration site, showing similar trends to laboratory studies with decreased alpha diversity and temporally differing beta diversity based on treatment phase. Enrichments in specific taxa were linked to the bioaugmentation culture and electron donor.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2021)
Article
Engineering, Environmental
Yuan Cao, Yue Li, Ling Ren, Mengqiao Sha, Dongqing Lv, Sen Wang, Fanlong Kong
Summary: This study successfully mitigated bio-clogging in constructed wetlands using rhamnolipids and citric acid as solubilizers, improving the removal efficiency of NH4+-N and COD.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Green & Sustainable Science & Technology
Jiong Zhang, Bowen Meng, Zhen Wang, Jingying Xiong, Wei Tang, Yiran Tan, Zhongze Zhang
Summary: This study investigates the cleaning effect of different cleaning methods and parameters on clogged pervious concrete pavement using computational fluid dynamics-discrete element method (CFDDEM) coupling. The results show that vacuum cleaning is effective in removing fine particles, while pressure washing has stronger impact force but limited cleaning capacity for deep layers. The optimal pressure washing angle is found to be 45 degrees to 60 degrees.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Environmental Sciences
Xue Ping, Yang Xian, Menggui Jin
Summary: The hyporheic zone (HZ), where surface water and groundwater interact in sediments beneath streams, has a significant impact on nutrient dynamics, particularly carbon and nitrogen cycling. This study examines the role of particulate organic carbon (POC) in influencing nitrate (NO3-) reduction within the HZ. The findings indicate that POC deposition enhances denitrification, leading to a higher NO3- removal efficiency and providing a more accurate estimate of NO3- removal potential in HZs.
WATER RESOURCES RESEARCH
(2023)
Article
Environmental Sciences
Fenglin Jin, Zhen Hu, Huaqing Liu, Jixin Su, Jian Zhang, Shuo Wang, Yanhui Zhao
Summary: Substrate clogging is a major challenge in the operation of subsurface flow constructed wetlands (SSF-CWs). This study investigated the impact of substrate clogging on phosphorus (P) accumulation behavior in SSF-CWs. Results showed that increasing clogging degree led to reduced P removal efficiency at low clogging degree, but higher P removal efficiency at high clogging degree. Substrate adsorption was the primary removal pathway in all SSF-CW systems, with higher Fe/Al-P accumulation on the substrate in the highly clogged system.
Article
Geosciences, Multidisciplinary
Shuyuan Wang, Dennis C. Flanagan, Bernard A. Engel, Madeline M. McIntosh
Summary: The study investigated the characteristics of sediment selectivity and transport rates under different subsurface hydrologic conditions in small laboratory flume channels. Results showed that the fraction of coarse-sized particles increased with increasing seepage head conditions. The determination of sediment transport capacity should consider both dynamic and spatial equilibrium conditions, with differences observed between free drainage and saturation conditions for the sediment transport capacity values.
Review
Geosciences, Multidisciplinary
Romain Dubuis, Giovanni De Cesare
Summary: Fine sediment plays a significant role in river solid flux and can lead to clogging of the riverbed, affecting aquatic habitat and fish reproduction. Numerous studies have explored the impact of clogging on aquatic fauna and examined various parameters involved in the deposition process. This review provides an overview of the physical mechanisms, analyzes different influencing factors, presents models for estimating the depth and quantity of deposition, and discusses research gaps.
EARTH-SCIENCE REVIEWS
(2023)
Article
Engineering, Environmental
Ying-hua Li, Lin-lin Peng, Hai-bo Li, De-ze Liu
Summary: Subsurface wastewater infiltration (SWI) is an environmentally friendly technology used for advanced treatment of domestic sewage, but the clogging of the porous medium is a key issue that needs to be addressed. Understanding the causes, development process, and solutions of clogging in SWI is different from that in constructed wetlands, and requires comprehensive analysis and research for effective prevention and management.
WATER SCIENCE AND TECHNOLOGY
(2021)
Review
Environmental Sciences
Chong Xu, Shiquan Sun, Yifu Li, Yang Gao, Wei Zhang, Liu Tian, Tian Li, Qing Du, Jingju Cai, Lean Zhou
Summary: Sediment is a major source of water pollution, and its remediation is crucial for water purification. Sediment microbial fuel cells (SMFCs) have gained attention for their ability to remove organic pollutants, compete with methanogens, and recover energy. This paper provides a comprehensive review on the recent advances of SMFCs in sediment remediation, including the advantages and disadvantages of current technologies, the principles and influencing factors of SMFCs, their applications in pollutant removal and remote monitoring, and strategies for enhancing their performance in sediment bioremediation. The drawbacks of SMFCs and future development directions are also discussed.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Construction & Building Technology
Xuhao Wang, Yuan Wang, Xingjian Ge, Bin Tong, Vern Schaefer, Kejin Wang, Cheng Li
Summary: Portland Cement Pervious Concrete (PCPC) is an effective means to address environmental issues and support sustainable growth. However, clogging is a major drawback in PCPC applications. This study quantitatively assessed the effects of clogging mechanisms on permeability and found that clay silty sand was more likely to cause clogging compared to sand and clay. Pressure washing followed by vacuuming was the most efficient rehabilitation method.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Jingsong Shan, Shanshan Feng, Feng Li, Shuyin Wu
Summary: Through clogging and permeability tests, this study found that the lateral permeability of PAC rapidly decreased with the increase of clogging cycle, especially after the first cycle. The permeable variation was strongly related to particle characteristics.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Multidisciplinary
Mohamed Monir Elzoghby, Zhonghua Jia, Wan Luo
Summary: Synthetic geotextile envelopes can be used as substitutes for sand filters in subsurface drainage pipes, but proper matching with soil is crucial to prevent clogging and soil loss. The study found that Typar SF27 met filtration requirements, while Typar SF20 presented higher risks of clogging and soil loss compared to SF27.
AIN SHAMS ENGINEERING JOURNAL
(2021)
Article
Environmental Sciences
Li Yang, Jie Gao, Ying Liu, Guoqiang Zhuang, Xiawei Peng, Wei-Min Wu, Xuliang Zhuang
Summary: Yellow mealworms are capable of biodegrading polystyrene and low-density polyethylene, forming new oxygen-containing functional groups and causing changes in physical and chemical properties. The biodegradation of PS is gut microbe-dependent, while LDPE biodegradation is less dependent on gut microbes. Gut microbial community significantly shift under different dietary conditions associated with the biodegradation of EPS and LDPE.
Article
Physics, Fluids & Plasmas
Yinuo Yao, Craig S. Criddle, Oliver B. Fringer
Summary: Industrial fluidized-bed reactors can be simplified in design and operation by approximating them as the superposition of corresponding monodispersed fluidized beds. However, in bidispersed fluidized beds, various characteristics such as volume fraction, velocity fluctuations, and stresses differ among the segregated layers at different particle Reynolds numbers. Particle velocity fluctuations and hydrodynamic stresses show significant variations in different layers as the particle Reynolds number changes.
PHYSICAL REVIEW FLUIDS
(2021)
Review
Astronomy & Astrophysics
Noah J. Langenfeld, Paul Kusuma, Tyler Wallentine, Craig S. Criddle, Lance C. Seefeldt, Bruce Bugbee
Summary: Nitrogen recycling is crucial for efficient food production in regenerative life support systems, while maintaining a pH below 7 in waste streams is necessary to reduce nitrogen volatilization. There is a great potential for nitrogen fixation and recycling in regenerative life support systems.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2021)
Article
Green & Sustainable Science & Technology
Sahar H. El Abbadi, Evan D. Sherwin, Adam R. Brandt, Stephen P. Luby, Craig S. Criddle
Summary: The production of methanotrophic microbial protein in the United States has the potential to replace fishmeal at competitive prices, reducing the demand for wild fisheries and capturing waste greenhouse gas emissions to feed fish in the aquaculture industry.
NATURE SUSTAINABILITY
(2022)
Article
Engineering, Environmental
Jing Gao, Liuwei Wang, Yong Sik Ok, Michael S. Bank, Jian Luo, Wei-Min Wu, Deyi Hou
Summary: This study challenges the belief that the ability of nanoplastics to mobilize other contaminants is solely due to direct adsorption. By using negatively charged polystyrene NPs, it was discovered that these NPs enhanced the leaching of arsenic but had no effect on cadmium leaching in historically contaminated soil. A novel indirect displacement model was developed to explain this phenomenon, and theoretical calculations and direct characterization were conducted to gain mechanistic insights. These findings provide valuable insights into NP-metal interactions in the natural soil environment and can contribute to future studies on NP transport and risk assessment.
Article
Environmental Sciences
Lijing Wang, Peter K. Kitanidis, Jef Caers
Summary: Bayesian inversion is commonly used to quantify uncertainty of hydrological variables. This paper proposes a hierarchical Bayesian framework to quantify uncertainty of both global and spatial variables. The authors present a machine learning-based inversion method and a local dimension reduction method to efficiently estimate posterior probabilities and update spatial fields. Using three case studies, they demonstrate the importance of quantifying uncertainty of global variables for predictions and the acceleration effect of the local PCA approach.
WATER RESOURCES RESEARCH
(2022)
Article
Environmental Sciences
Shan-Shan Yang, Meng-Qi Ding, Xin-Ran Ren, Zhi-Rong Zhang, Mei-Xi Li, Li-Li Zhang, Ji-Wei Pang, Cheng-Xin Chen, Lei Zhao, De-Feng Xing, Nan-Qi Ren, Jie Ding, Wei-Min Wu
Summary: Yellow and dark mealworms are able to biodegrade commercial polyethylene materials at a high rate, and the extent of biodegradation is influenced by the polymer type, molecular weight, branching, and crystallinity degree.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Water Resources
Mojtaba Forghani, Yizhou Qian, Jonghyun Lee, Matthew Farthing, Tyler Hesser, Peter K. Kitanidis, Eric F. Darve
Summary: This article presents a reduced-order model (ROM) based approach that utilizes a variational autoencoder (VAE) to compress bathymetry and flow velocity information, allowing for fast solving of bathymetry inverse problems. By constructing ROMs on a nonlinear manifold and employing a Hierarchical Bayesian setting, variational inference and efficient uncertainty quantification can be achieved using a small number of ROM runs.
ADVANCES IN WATER RESOURCES
(2022)
Article
Green & Sustainable Science & Technology
Bo-Yu Peng, Ying Sun, Zeyu Wu, Jiabin Chen, Zheng Shen, Xuefei Zhou, Wei-Min Wu, Yalei Zhang
Summary: This study characterized the biodegradation of polystyrene (PS) and low-density polyethylene (LDPE) by Zophobas atratus larvae over a 28-day test period. The larvae were able to degrade PS and LDPE into microplastic particles, providing new insights into insect-mediated biodegradation of persistent plastics.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Environmental Sciences
Xueyuan Kang, Amalia Kokkinaki, Xiaoqing Shi, Hongkyu Yoon, Jonghyun Lee, Peter K. Kitanidis, Jichun Wu
Summary: This study presents a framework that combines a deep-learning-based inversion method with a process-based upscaled model to estimate source zone architecture (SZA) metrics and mass discharge from sparse data. By improving the estimation method, the upscaled model accurately reproduces the concentrations and uncertainties of multistage effluents, providing valuable input for decision making in remediation applications.
WATER RESOURCES RESEARCH
(2022)
Article
Engineering, Environmental
Bo-Yu Peng, Ying Sun, Shaoze Xiao, Jiabin Chen, Xuefei Zhou, Wei-Min Wu, Yalei Zhang
Summary: Mealworms are capable of degrading polystyrene, but the molecular weight of polystyrene affects the degradation process and the response of mealworms. By feeding mealworms with polystyrene microplastics of different molecular weights, the study investigated the degradation of polystyrene, gut microbiome, and metabolome. The findings reveal that mealworms can degrade polystyrene through broad or limited depolymerization, and the degradation process leads to changes in their gut microbiome and metabolome.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Meng-Qi Ding, Shan-Shan Yang, Jie Ding, Zhi-Rong Zhang, Yi-Lin Zhao, Wei Dai, Han-Jun Sun, Lei Zhao, Defeng Xing, Nanqi Ren, Wei-Min Wu
Summary: The biodegradation of low-density polyethylene (LDPE) foam by Tenebrio molitor and Tenebrio obscurus larvae was examined with different co-diets. The presence of co-diets enhanced LDPE consumption and degradation, and different diet types influenced gut microbial diversity, metabolic pathways, and functions. Wheat bran or corn flour co-diets showed the highest effectiveness for larval development and LDPE degradation.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Environmental Sciences
Simon Meunier, Peter K. Kitanidis, Amaury Cordier, Alan M. MacDonald
Summary: This study develops a numerical model to simulate the abstraction capacities of photovoltaic water pumping systems across Africa using openly available data. The model includes realistic geological constraints on pumping depth and sub-hourly irradiance time series. The simulation results show that for much of Africa, groundwater pumping using photovoltaic energy is limited by aquifer conditions rather than irradiance. These findings can help identify regions with high potential for photovoltaic pumping and guide large-scale investments.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)
Article
Engineering, Environmental
Bo-Yu Peng, Shaoze Xiao, Ying Sun, Yurong Liu, Jiabin Chen, Xuefei Zhou, Wei-Min Wu, Yalei Zhang
Summary: This study investigates the possibility of generating microplastics (MPs) and nanoplastics (NPs) during the biodegradation of plastics by mealworms. The results show that mealworms can break down plastics into MPs but NPs were not detected. This provides important insights into the factors controlling MP and NP generation during macroinvertebrate-mediated plastic biodegradation.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Lei He, Shan -Shan Yang, Jie Ding, Zhi-Li He, Ji-Wei Pang, De-Feng Xing, Lei Zhao, He -Shan Zheng, Nan-Qi Ren, Wei-Min Wu
Summary: In this study, it was demonstrated that mealworms were able to rapidly biodegrade PET with high efficiency, with a reduction in mass and molecular weight. The gut microbial community of the mealworms played a crucial role in PET degradation, and various metabolic pathways were up-regulated in response to PET intake. This research provides new insights into the adaptation of gut microbes to a PET diet and their contribution to PET degradation.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
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.
