Article
Agricultural Engineering
Radhika Deore, Rakesh Kumar, Mohammad Waqqas Mirza, Abid Ali Khan
Summary: The study investigated the suitability of three different sludge collected from diverse environments for anammox process establishment. The microbial community in the seed sludge was studied, and it was found that anammox bacteria were present only in the seed sludge treating high NH4+-N wastewater. The abundance of anammox and denitrifying bacteria in the seed sludge was influenced by the influent NH4+-N, NO3--N, and organic carbon concentrations, which in turn impacted the anammox start-up.
BIORESOURCE TECHNOLOGY
(2022)
Article
Engineering, Environmental
Jia Meng, Zhetai Hu, Zhiyao Wang, Shihu Hu, Yanchen Liu, Hongguang Guo, Jianzheng Li, Zhiguo Yuan, Min Zheng
Summary: This study provides a comprehensive assessment of the novel acidic nitrification process and identifies the key factors governing stable nitrite accumulation. The results suggest that stable nitrite accumulation can be maintained under various influent and operational conditions as long as a ppm-level of free nitrous acid (FNA) is established. Furthermore, specific ammonia-oxidizing microbial communities were observed under these conditions.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Yu Xue, Min Zheng, Zhao Cheng, Siqi Li, Shaolin Yang, Yanchen Liu, Yi Qian, Xia Huang
Summary: In this study, the researchers successfully achieved acidic partial nitritation (PN) under dynamic pH changes and investigated the microbial communities involved. They also developed a model to predict the shifting of nitrifying microbial communities during the establishment of acidic PN. The outcomes of this study can support the optimal design of acidic PN-based short-cut nitrogen removal processes.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Review
Environmental Sciences
Hussein E. Al-Hazmi, Xi Lu, Dominika Grubba, Joanna Majtacz, Michael Badawi, Jacek Makinia
Summary: This review highlights the importance of understanding microbial metabolism in anammox-mediated systems and their potential applications in sustainable nitrogen removal from wastewater. Various processes, including PN-A, SNAD, PD-A, and DAMO-A, have shown efficient N removal in different wastewater treatment scenarios. The review also discusses the production of N2O in anammox-based processes and how it relates to certain bacteria. Additionally, mathematical models and promising NO3- reduction technologies are discussed. Overall, this review provides valuable insights into sustainable N removal in anammox-mediated systems, encouraging further research in this field.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Alexander Schopf, Kathlyn M. Kirkwood, Alexandra Tsitouras, Robert Delatolla
Summary: The study demonstrates that a moving bed biofilm reactor system operating under a novel design strategy can achieve robust partial nitritation and oxidation of ammonia without the need for intense operational measures. By suppressing the activity of nitrite oxidizing bacteria (NOB) rather than reducing their population, the system effectively promotes nitritation and oxidation processes.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Environmental Sciences
Huiyang Wen, Hui Zhu, Yingying Xu, Baixing Yan, Brian Shutes, Gary Banuelos, Xinyi Wang
Summary: This study found that glucose outperformed other carbon sources in MFC-CWs, with moderate concentration (200 mg L-1) resulting in the best removal of SMX and TC. The highest removal percentages of SMX and TC were obtained in MFC-CWs with an external resistance of 700 Omega. Aeration for 12 hours was shown to improve the removal efficiency of antibiotics in MFC-CWs.
ENVIRONMENTAL POLLUTION
(2021)
Article
Computer Science, Interdisciplinary Applications
Jeffrey Wade, Christa Kelleher, Barret L. Kurylyk
Summary: This study developed a physically-based water temperature model coupled with the National Water Model (NWM) to assess the potential for water temperature prediction to be incorporated into the NWM at the continental scale. By evaluating different model configurations of increasing complexity, the study successfully simulated hourly water temperatures in the forested headwaters of H.J. Andrews Experimental Forest in Oregon, USA, providing a basis for integrating water temperature simulation with predictions from the NWM.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Engineering, Environmental
Clara Reino, Julian Carrera
Summary: The study focused on the performance of partial nitritation process under mainstream conditions, revealing that changes in SRT, DO concentration, and temperature have a significant impact on the development of nitrifying community, especially the dynamics of NOB population. Long-term exposure to low temperature and subsequent temperature variability influenced the competitiveness among nitrifiers and the growth of species previously undetected.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Environmental Sciences
Suin Park, Kyungjin Cho, Taeho Lee, Eunsu Lee, Hyokwan Bae
Summary: Partial nitritation is essential for cost-effective nitrogen removal processes. In this study, the abundant bacterial communities responsible for nitrification under salt stress conditions were investigated. The results showed that adaptation and selection were simultaneous mechanisms in the nitrifying process under salt stress conditions. Salinity and ammonia loading rates were important process parameters determining the nitrifying bacterial community.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Chemical
James Odgers, Chrysoula Kappatou, Ruth Misener, Salvador Garcia Munoz, Sarah Filippi
Summary: This article presents an approach based on bootstrapping to model the uncertainty in partial least squares (PLS), which is difficult due to the nonlinear effect of the observed data on the latent space. The approach allows for equally representing confidence intervals for points close to or far away from the latent space. Applications in determining the Design Space for industrial processes and modeling the uncertainty of spectroscopy data demonstrate the benefits and performance of the method.
Article
Environmental Sciences
Jacob Kidmose, Lars Troldborg, Jens Christian Refsgaard
Summary: Post audits are the final step in the modeling protocol, where original model predictions are tested with new data. The evaluation of model predictions and associated uncertainty showed that the original model underestimated uncertainty compared to the updated post audit model.
Article
Engineering, Environmental
Matthew J. Wade, Gail S. K. Wolkowicz
Summary: Low-energy nitrogen removal technologies such as PN/A have gained attention in the water industry for their potential in reducing energy consumption and sludge production. Mathematical modeling, such as the simplified mechanistic model presented in this study, offers insights into optimizing operating conditions for maximizing efficiency. Mapping process performance data onto parameter spaces can help engineers target suitable operating regimes for specific objectives, such as maximizing nitrogen removal efficiency or reducing oxygen requirements.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Engineering, Environmental
Dawoon Jeong, Hyunman Lim, Weonjae Kim
Summary: This study investigated a combined partial nitritation and anammox process for treating low-strength ammonia synthetic wastewater at 20 degrees C. Limited dissolved oxygen concentrations suppressed nitrite-oxidizing bacteria activity, but an undesired nitrite oxidation rate was observed at 20 degrees C.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Chemistry, Medicinal
Wanlei Wei, Hervei Hogues, Traian Sulea
Summary: The demand for protein engineering in different pH environments has driven the development of computational algorithms to evaluate large sets of protein residues and point mutations. This study systematically tested seven fast and accessible approaches and found that DeepKa, PKAI+, PROPKA3, and H++ performed well. Combining the best empirical predictors into simple consensuses improved the overall accuracy and transferability.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Construction & Building Technology
A. B. M. A. Kaish, Temple Chimuanya Odimegwu, Ideris Zakaria, Manal Mohsen Abood, Lutfun Nahar
Summary: Water treatment plants generate alum sludge as waste during the treatment process, which can be used as a partial replacement for fine aggregate in concrete to improve density, strength, and durability. Studies show that at an optimal replacement content of 10%, the sludge can produce workable concrete with improved properties.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Environmental
Jing Zhao, Tao Liu, Jia Meng, Zhetai Hu, Xuanyu Lu, Shihu Hu, Zhiguo Yuan, Min Zheng
Summary: The significance of residual ammonium concentration to the mainstream PN/A biofilm system was systematically investigated. The study found that a residual NH4+ concentration of -50 mg N/L was essential to stable nitrite-oxidizing bacteria (NOB) suppression, while a lower concentration of -5 mg N/L caused NOB proliferation. High NH4+ concentration promoted the activity of ammonia oxidizing bacteria (AOB) and reduced oxygen penetration depth. These findings provide important knowledge for process control and expand the understanding of microbial interactions in mainstream PN/A biofilm systems.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Xi Lu, Zhiyao Wang, Haoran Duan, Ziping Wu, Shihu Hu, Liu Ye, Zhiguo Yuan, Min Zheng
Summary: The study investigated the production and pathways of nitric oxide (NO) and nitrous oxide (N2O) during acidic sludge digestion. It was found that a significant amount of total nitrogen (TN) was lost, with 40% emitted as NO and 8% as N2O. Batch assays revealed that nitrite reduction and endogenous microbial activities played a role in this process.
Article
Engineering, Environmental
Zhetai Hu, Tao Liu, Zhiyao Wang, Jia Meng, Min Zheng
Summary: This study proposes a novel wastewater treatment scheme that combines chemically enhanced primary treatment (CEPT), partial nitritation and anammox (PN/A), and anaerobic digestion (AD) to achieve energy-neutral wastewater treatment. By adding FeCl3 to the CEPT process, high removal rates of COD and phosphate were achieved, and alkalinity was reduced. Stable accumulation of nitrite was achieved in an aerobic reactor using a novel acid-tolerant ammonium-oxidizing bacteria (AOB), Candidatus Nitrosoglobus. After polishing in an anoxic reactor (anammox), satisfactory effluent quality was obtained. The integrated system demonstrated stable performance and could achieve energy self-sufficiency.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Zhetai Hu, Shihu Hu, Liu Ye, Haoran Duan, Ziping Wu, Pei-Ying Hong, Zhiguo Yuan, Min Zheng
Summary: This study presents a new technology roadmap for wastewater management, focusing on resource recovery rather than pollutant removal. A novel use of FeCl3 in an integrated anaerobic wastewater treatment and anammox process was developed, showing stable suppression of nitrite-oxidizing bacteria and excess sludge reduction. Experimental assessments using a laboratory-scale system demonstrated good effluent quality, with potential for phosphorus recovery and bioenergy production. The system was found to have low energy consumption and a net energy production of about 0.11 kWh/m3-wastewater.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Ecology
Yan Zhang, Tao Liu, Meng-Meng Li, Zheng-Shuang Hua, Paul Evans, Yanni Qu, Sha Tan, Min Zheng, Hui Lu, Jian-Yu Jiao, Sebastian Lucker, Holger Daims, Wen-Jun Li, Jianhua Guo
Summary: The recent discovery of comammox Nitrospira species capable of complete ammonia oxidation in non-marine thermal habitats expands our understanding of microbial nitrification. This study reports the wide distribution of comammox Nitrospira in terrestrial hot springs and provides new insights into their metabolic activity and thermal adaptation.
Article
Environmental Sciences
Zhetai Hu, Shihu Hu, Pei-Ying Hong, Xueqin Zhang, Veljko Prodanovic, Kefeng Zhang, Liu Ye, Ana Deletic, Zhiguo Yuan, Min Zheng
Summary: Anaerobic treatment of domestic wastewater has advantages over conventional aerobic treatment in terms of lower biomass yield, lower energy demand and higher energy recovery. However, it faces issues of excessive phosphate and sulfide in effluent, as well as excess H2S and CO2 in biogas. This study proposes an electrochemical method that generates Fe2+ in the anode and hydroxide ion (OH-) and H2 in the cathode to overcome these challenges. The results show that dosing of the electrochemically generated iron significantly improves the performance of anaerobic wastewater treatment, increasing COD removal efficiency, CH4 production rate, dissolved sulfide reduction, and phosphate removal efficiency, while upgrading the quality of biogas by reducing CO2 and H2S contents.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Veljko Prodanovic, Kefeng Zhang, Min Zheng, Shihu Hu, Pei-Ying Hong, Zhiguo Yuan, Ana Deletic
Summary: Vegetated biofiltration systems are widely used for urban stormwater and greywater treatment, but the impact of high ammonium strength wastewater on nitrification process is not well understood. A laboratory-based column study was conducted to investigate dominant nitrification mechanisms. The results showed that appropriate aerobic contact time, oxygenation and alkalinity buffering are necessary for effective nitrification.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Mengxiong Wu, Chun -Yu Lai, Yulu Wang, Zhiguo Yuan, Jianhua Guo
Summary: Nitrate contamination is a common problem in water environments and poses health risks. This study investigates the feasibility of using propane and butane as electron donors for nitrate reduction. The results showed that propane and butane could continuously remove nitrate under oxygen-limiting conditions, and certain microorganisms were responsible for the oxidation of these gases and the reduction of nitrate.
Article
Engineering, Environmental
Zhiqiang Zuo, Yan Chen, Yaxin Xing, Siqi Li, Shaolin Yang, Guangming Jiang, Tao Liu, Min Zheng, Xia Huang, Yanchen Liu
Summary: A stable nitrification process was developed in a two-stage bioreactor, successfully converting half of the ammonium in high-strength urine into nitrate, forming valuable ammonium nitrate solution with full nutrient recovery. This method could reduce energy input by 43%, greenhouse gas emission by 40%, and cost by 33% compared to conventional wastewater management.
Article
Engineering, Environmental
Zhiqiang Zuo, Yaxin Xing, Haoran Duan, Daheng Ren, Min Zheng, Yanchen Liu, Xia Huang
Summary: This study presents an alternative solution to reduce sulfide and methane production in sewer sediments by integrating urine source separation, rapid storage, and intermittent dosing into a sewer. The experimental results showed that the proposed urine dosing effectively reduced sulfide and methane production, and also had economic and environmental advantages compared to conventional chemical methods.
Article
Engineering, Environmental
Min Zheng, Huijuan Li, Haoran Duan, Tao Liu, Zhiyao Wang, Jing Zhao, Zhetai Hu, Shane Watts, Jia Meng, Peng Liu, Maxime Rattier, Eloise Larsen, Jianhua Guo, Jason Dwyer, Ben Van Den Akker, James Lloyd, Shihu Hu, Zhiguo Yuan
Summary: A pilot-scale mainstream anammox process was implemented in an Integrated Fixed-film Activated Sludge configuration, achieving stable operation with robust NOB suppression. Three key control strategies were integrated, including low dissolved oxygen, regular FNA-based sludge treatment, and residual ammonium concentration control.
Article
Engineering, Environmental
Mei Bai, Zhiyao Wang, James Lloyd, Dilini Seneviratne, Thomas Flesch, Zhiguo Yuan, Deli Chen
Summary: As the wastewater sector aims to achieve net zero greenhouse gas (GHG) emissions, understanding and quantifying fugitive emissions from different sewage treatment steps are crucial for developing effective GHG abatement strategies. A study in an Australian wastewater treatment plant measured methane (CH4) emissions from a sludge drying pan (SDP) using micrometeorological techniques and open-path lasers for over a year. The emission rate was closely linked to sludge additions, climate, and operational processes. The study found a mean emission rate of 2.3 (+/- 0.8) g m^-2 d^-1 during the 90 weeks after initial sludge addition, resulting in cumulative emissions of approximately 32 t of CH4.
Article
Engineering, Environmental
Yu Xue, Min Zheng, Zhao Cheng, Siqi Li, Shaolin Yang, Yanchen Liu, Yi Qian, Xia Huang
Summary: In this study, the researchers successfully achieved acidic partial nitritation (PN) under dynamic pH changes and investigated the microbial communities involved. They also developed a model to predict the shifting of nitrifying microbial communities during the establishment of acidic PN. The outcomes of this study can support the optimal design of acidic PN-based short-cut nitrogen removal processes.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Jiuling Li, Nur Nabilah Naina Mohamad, Keshab Sharma, Zhiguo Yuan
Summary: Establishing efficient boundary conditions is crucial for modeling heat transfer in sewers and recovering heat from wastewater. This study presents a novel approach using Fourier transform and data-driven models to determine the thickness of the soil layer and predict temperatures at the soil-layer boundary. The methodology improves the accuracy and speed of sewer heat transfer modeling.
