Article
Environmental Sciences
Joao Monteiro Neto, Lorena Gotelip Costalonga, Nathacha Oliveira Pires, Thais Girardi Carpanez, Fernanda Bento Rosa Gomes, Sue Ellen Costa Bottrel, Jonathas Batista Gonsalves Silva, Marcelo Henrique Otenio, Renata de Oliveira Pereira
Summary: The presence and removal of estrogen-like endocrine disrupting chemicals (EEDC) in dairy cattle wastewaters during anaerobic digestion were investigated in this study. The results showed that anaerobic digestion was not efficient in EEDC removal, and the application of an artificial insemination protocol did not contribute to the increase of EEDC concentrations in dairy cattle wastewater. The reuse of wastewater for cleaning and fertigation in dairy production systems can be beneficial in terms of water conservation and organic matter and nutrient recycling. However, the potential environmental and health risks associated with EEDC in dairy cattle wastewaters need further elucidation and evaluation.
SCIENCE OF THE TOTAL ENVIRONMENT
(2024)
Article
Environmental Sciences
Ke He, Ethan Hain, Anne Timm, Lee Blaney
Summary: This study investigated the accumulation of estrogenic hormones and UV-filters in red swamp crayfish, finding that UV-filters had higher concentrations than estrogenic hormones in crayfish tail tissue after exposure to environmentally relevant concentrations. The EDC concentrations in the crayfish tail tissue remained relatively stable throughout the exposure period.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Review
Endocrinology & Metabolism
Wiwat Rodprasert, Jorma Toppari, Helena E. Virtanen
Summary: Endocrine disrupting chemicals, particularly antiandrogenic EDCs, may impact male reproductive health, especially when exposed during fetal development at the sensitive 'masculinization programming window'.
FRONTIERS IN ENDOCRINOLOGY
(2021)
Article
Environmental Sciences
Lidia Gaudencio Ribeiro Silva, Elizangela Pinheiro Costa, Maria Clara Vieira Martins Starling, Taiza dos Santos Azevedo, Sue Ellen Costa Bottrel, Renata Oliveira Pereira, Ananda Lima Sanson, Robson Jose Cassia Franco Afonso, Camila C. Amorim
Summary: The study evaluated the removal of endocrine disruptors and estrogenic activity in wastewater treatment plant effluent using LED irradiated photo-Fenton process. The results showed that under optimal experimental conditions, LED photo-Fenton was effective in removing endocrine disruptors and part of the estrogenic activity in the effluent.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Review
Environmental Sciences
Pearl Isabellah Murungi, Aliyu Adebayo Sulaimon
Summary: Petroleum sludge is a solid emulsified waste and contaminant commonly produced in the petroleum industry. This review aims to introduce various methods for the treatment of petroleum sludge and evaluate their suitability.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Engineering, Environmental
S. F. Ahmed, M. Mofijur, Samiha Nuzhat, Anika Tasnim Chowdhury, Nazifa Rafa, Md. Alhaz Uddin, Abrar Inayat, T. M. I. Mahlia, Hwai Chyuan Ong, Wen Yi Chia, Pau Loke Show
Summary: Various treatment technologies have been developed for the removal of emerging contaminants (ECs) from wastewater, with hybrid systems being found to be more efficient compared to individual technologies. A hybrid technique combining ozonation with activated carbon has been particularly effective in removing certain ECs, such as pharmaceuticals and pesticides. While nanotechnology shows promise, extensive research and development are necessary to fully and effectively remove ECs from wastewater.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Environmental Sciences
T. Leiviska, S. Risteela
Summary: The study examined the occurrence of pharmaceuticals, hormones, and bacterial community structures at a wastewater treatment plant in Finland with two parallel treatment lines. It found that there were fluctuations in species richness and diversity in the effluent samples, with a marked decrease observed between August and November. The study also showed differences in removal rates between conventional activated sludge treatment and membrane bioreactor treatment.
ENVIRONMENTAL POLLUTION
(2022)
Article
Engineering, Environmental
Rafiquel Islam, Richard Man Kit Yu, Megan Andrew-Priestley, Nathan Smith, Mohammad Mahmudur Rahman, Thi Kim Anh Tran, Wayne A. O'Connor, Geoff R. MacFarlane
Summary: This study analyzed the loads and efficiency of estrogenic compounds in Australian WWTWs, showing significant reduction of most target compounds during the treatment process, with no ecological risk predicted in the effluents.
Article
Biochemical Research Methods
Miguel Cobo Golpe, Gabriela Castro, Maria Ramil, Rafael Cela, Ysabel Santos, Isaac Rodriguez
Summary: This study optimized and validated a method based on MSPD and LC-MS/MS for the sensitive and selective determination of chlorhexidine in sludge from STPs. Analysis of samples from different STPs in Northwest Spain revealed the presence of chlorhexidine, which may impact microbial populations but is unlikely to affect plant germination.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2022)
Article
Environmental Sciences
Damien Alain Devault, Laurence Amalric, Sebastien Bristeau, Justine Cruz, Nathalie Tapie, Sara Karolak, Helene Budzinski, Yves Levi
Summary: The study on removal of 61 emerging micropollutants in a biofilter wastewater treatment plant in Martinique showed a high removal efficacy of 92% with paracetamol and caffeine contributing significantly to the overall removal. The adsorption of some molecules on sludge raised concerns about local soil pollution from sludge spreading.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Engineering, Environmental
Cyntia Ely, Irina S. Moreira, Joao Paulo Bassin, Daniela P. Mesquita, Joana Costa, Eugenio C. Ferreira, Marcia W. C. Dezotti, Paula M. L. Castro
Summary: An AGS SBR reactor adapted to salinity was used for the treatment of synthetic saline wastewater containing EDCs. The results showed that E2 was completely biodegraded, while the removal efficiency of EE2 and BPA was lower. The activity of phosphate-accumulating organisms was affected by EDCs, but the activity of ammonium- and nitrite-oxidizing bacteria was not significantly affected. The microbial diversity increased after the addition of EDCs.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Public, Environmental & Occupational Health
Vicente Mustieles, Juan-Pedro Arrebola, Miquel Porta
Summary: Citizens should have access to regulatory changes and policies that prioritize the needs of humans, the climate, and nature. We draw on past experiences of preventable human suffering and economic losses caused by delayed regulation of both old and new pollutants. It is crucial for health professionals, the media, and citizens' organizations to increase awareness of environmental health issues. Improving the translation of research into clinical practices and policies is necessary to reduce the burden of diseases caused by exposure to environmental chemicals. There are valuable lessons to be learned from previous science-to-policy processes and current trends in regulating pollutants.
PREVENTIVE MEDICINE
(2023)
Article
Environmental Sciences
Katekanya Tadsuwan, Sandhya Babel
Summary: This study compares the efficiency of microplastic removal in two wastewater treatment plants in Bangkok and finds that wastewater treatment plants equipped with ultrafiltration have higher removal efficiency.
Article
Chemistry, Multidisciplinary
Maria Teresa Santos, Pedro Andre Lopes
Summary: The industrial sector produces large amounts of sludge, which can be treated and recovered using various methods. Through experiments, it was found that anaerobic co-digestion followed by the production of heterogeneous catalysts for biodiesel production is the most promising method.
SUSTAINABLE CHEMISTRY AND PHARMACY
(2022)
Article
Environmental Sciences
Raffaele Morello, Francesco Di Capua, Giovanni Esposito, Francesco Pirozzi, Umberto Fratino, Danilo Spasiano
Summary: Excess sludge production in wastewater treatment plants is a global environmental issue. Finding suitable technological solutions and understanding the mechanisms, advantages, disadvantages, and economic and environmental impact of each technology are crucial.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Environmental Sciences
Wesley Olaya, Hina Dilawar, Cigdem Eskicioglu
Summary: The study found that ZnO NPs have inhibitory effects at medium and high levels (75 and 100 mg ZnO/g TS). Coated nanoparticles had less inhibition than non-coated nanoparticles. Thermophilic bacteria were more sensitive to ZnO NPs compared to mesophilic bacteria.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Agricultural Engineering
M. R. Atelge, A. E. Atabani, Serdar Abut, M. Kaya, Cigdem Eskicioglu, Georgeio Semaan, Changsoo Lee, Y. S. Yildiz, S. Unalan, R. Mohanasundaram, F. Duman, Gopalakrishnan Kumar
Summary: The study found that oil extraction from spent coffee grounds as a pre-treatment strategy has a positive impact on increasing methane yield. Moreover, co-digestion of defatted spent coffee grounds with spent tea waste, glycerin, and macroalgae showed potential advantages. Additionally, a triple mix of defatted spent coffee grounds, spent coffee grounds, and spent tea waste outperformed other mixed substrates.
BIORESOURCE TECHNOLOGY
(2021)
Review
Engineering, Environmental
Huan Liu, Guangji Hu, Ibrahim Alper Basar, Jianbing Li, Nathalie Lyczko, Ange Nzihou, Cigdem Eskicioglu
Summary: Phosphorus is a critical non-renewable resource, and its recovery and recycling are essential for meeting future P demands and environmental conservation. Wet-chemical extraction and precipitation techniques have shown effectiveness in recovering phosphorus from sludge-derived ash and hydrochar. Different extraction methods have their own advantages and disadvantages, with sequential extraction showing promising efficiency and low metal interferences.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Green & Sustainable Science & Technology
Vikas Kumar, Resty Nabaterega, Shiva Khoei, Cigdem Eskicioglu
Summary: Microbial communities play a crucial role in various biochemical and metabolic reactions in natural and engineered anaerobic systems. Understanding electron transfer and interactions between microbial communities is essential for effective biological treatment processes and bioenergy production. Direct interspecies electron transfer (DIET) and the use of nanoparticles show promise for enhancing methane production and interspecies interactions.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Engineering, Environmental
Hina Dilawar, Cigdem Eskicioglu
Summary: The increase in production of biobased plastics has led to the need for studying their degradation. This study examined the biodegradability of a biocomposite cellphone case under different laboratory and field conditions. The results showed that composting was more effective than anaerobic conditions in degrading the cellphone case.
Article
Green & Sustainable Science & Technology
Vikas Kumar, Brandon Kieft, Parmila Devi, Steven J. Hallam, Cigdem Eskicioglu
Summary: This study investigated the effects of two-step activated carbon cloth on syntrophic microbial associations during anaerobic digestion of municipal sludge. The results showed that activated carbon cloth enhanced methane yield and reduced the lag phase, attributed to its increased electron transfer and methane production kinetics. Additionally, activated carbon cloth promoted the adherence of methane-producing microorganisms, providing a stable environment for syntrophic energy metabolism.
Article
Green & Sustainable Science & Technology
Resty Nabaterega, Brandon Kieft, Steven J. Hallam, Cigdem Eskicioglu
Summary: This study successfully optimized the conditions for volatile fatty acids (VFAs) production from municipal sludge using fractional factorial design and response surface methodology. It was found that acid fermenters with the optimized conditions harbored a high proportion of fermentative bacteria, mainly Clostridia, and had low community diversity.
Article
Engineering, Environmental
Huan Liu, Ibrahim Alper Basar, Nathalie Lyczko, Ange Nzihou, Cigdem Eskicioglu
Summary: This study evaluated the use of hydrothermal liquefaction as a sustainable method to convert municipal sewage sludge into renewable energy source, biocrude. The effects of reaction temperature and residence time on biocrude yield and quality were investigated using response surface methodology. The study found that optimizing the reaction conditions resulted in maximized biocrude yield and energy recovery. The composition and quality of the biocrude were influenced by the reaction temperature. Upgrading and recovering trace metals from the biocrude were also found to be necessary. These findings contribute to the advancement of biorefinery technology and can guide the design of full-scale sludge treatment systems.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Green & Sustainable Science & Technology
Huan Liu, Nathalie Lyczko, Ange Nzihou, Cigdem Eskicioglu
Summary: This study comprehensively assessed the properties, environmental influences, and possible utilizations of hydrochar generated from mixed sludge. With the increase of HTL reaction temperatures and residence time, the dry-weight contents of ash and fuel ratio increased while the drybasis contents of volatile matter, carbon, and higher heating value sharply decreased. Hydrochar performed more stable combustion than sludge, but its high ash contents and alkali index implied high risks of slagging and fouling. Hydrochar has a good potential for carbon sequestration and metals and nutrient recovery.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Biotechnology & Applied Microbiology
Resty Nabaterega, Bita Nazyab, Cigdem Eskicioglu
Summary: The study modified the ADM1 to simulate VFA production from municipal sludge. The model was calibrated using experimental data and showed good accuracy in simulating acetic, propionic, and butyric acids. However, it underestimated acetic acid production in the validation using an independent data set. The results extend the applicability of the ADM1 in simulating VFA during anaerobic fermentation.
BIOCHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Ibrahim Alper Basar, Huan Liu, Cigdem Eskicioglu
Summary: This study characterized HTL aqueous samples and identified their composition, including compounds such as N-heterocyclics, VFAs, amides, ketones, amines, and phenolics. The COD levels of HTL aqueous samples were 87-103 g/L. Pretreatment is necessary for detoxification of HTL aqueous before biological treatment.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Thermodynamics
Huan Liu, Ibrahim Alper Basar, Cigdem Eskicioglu
Summary: Hydrothermal liquefaction (HTL) is a technology that converts waste biomass into a biofuel known as biocrude. This study found that more than 64% of energy could be recovered as biocrude from mixed primary and secondary sludge under HTL conditions. The study also identified concerns about the accumulation of heavy metals in hydrochar, one of the waste streams generated by the HTL process.
Article
Engineering, Environmental
Huan Liu, Nathalie Lyczko, Ange Nzihou, Cigdem Eskicioglu
Summary: This study evaluated the effects of extraction conditions on the release of phosphorus and metals from hydrochar using nitric acid. Acid normality, liquid-to-solid ratio, and contact time had positive effects on leaching efficiencies, while decreasing eluate pH improved leaching efficiencies of phosphorus and metals. The best extraction condition was using 0.6 N HNO3 at a liquid-to-solid ratio of 10 mL/g for 2 hours.
Article
Engineering, Environmental
Resty Nabaterega, Ibrahim Alper Basar, Cigdem Eskicioglu
Summary: This study investigates the optimization of volatile fatty acids (VFAs) production through anaerobic digestion (AD) by evaluating the impact of digester sludge retention time (SRT), temperature, and pH on the reactor performance. The results show that fermenters operated at high pH of 8, low SRT of 2 days, and varying temperatures of 55 and 45 degrees C have the highest VFAs production. Batch acidogenic assays provide quantitative information regarding the presence and activities of cultures in continuously-fed AD, offering insights for utilizing more complex substrates.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Review
Engineering, Environmental
Resty Nabaterega, Vikas Kumar, Shiva Khoei, Cigdem Eskicioglu
Summary: Although two-staged anaerobic digestion (AD) is not a new process, there is limited and inconsistent information on process stability and optimum operating conditions for improving overall performance and resource recovery. This study reviews critical operating conditions and AD treatment options for municipal wastewater treatment plants to identify the best two-staged AD systems using methods like multi-criteria evaluation, principal component analysis (PCA), and energy balances. The analysis shows that the thermophilic-mesophilic (T-M) two-staged AD system is the most effective in terms of volatile solids removal, methane yield, pathogen reduction, and dewaterability compared to other configurations.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
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.
