Article
Biotechnology & Applied Microbiology
Soroush Dabiri, Johannes Sappl, Prashant Kumar, Michael Meister, Wolfgang Rauch
Summary: Sludge recirculation mixing is crucial for the stable operation of anaerobic digesters, with the configuration of the sludge inlet significantly influencing process efficiency. Computational fluid dynamics was used to investigate the effect of inlet configuration, with single-phase and multi-phase models applied for submerged and splashing inlets. A surrogate single-phase model was developed to reduce computational demand, showing promising results in terms of reducing dead volume and simulation clock time.
BIOPROCESS AND BIOSYSTEMS ENGINEERING
(2021)
Article
Engineering, Environmental
Anand Kumar Saini, Kunwar Paritosh, Amit Kumar Singh, Vivekanand Vivekanand
Summary: This study used CFD simulation to analyze the flow dynamics of a working sewage treatment plant, determining the optimal geometric configuration for mixing with minimum power consumption. Multiple inlet planes were found to be more efficient than single plane inlets, providing insights for future design and operation of sewage treatment plants.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Engineering, Environmental
Peng Wei, Wim Uijttewaal, Henri Spanjers, Jules B. van Lier, Merle de Kreuk
Summary: This study used computational fluid dynamics (CFD) to assess the impact of treated sludge rheology on flow and mixing characterisation in a full-scale biogas-mixed digester. The results showed that the applied gas-sparging induced insufficient flow and mixing, but contributed to the well-functioning of the digester. To correctly assess flow and mixing, the applied rheological data should be in agreement with the type of sludge that is treated in the digester.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Mechanics
A. Haque, A. K. Nayak, S. Bhattacharyya
Summary: This study examines the mixing performance in a modulated micro-channel filled with non-Newtonian power-law fluid by considering the combined effects of geometrical and surface potential heterogeneity. Analytical solutions are obtained for the electric potential and velocity, while Poisson-Nernst-Planck-Navier-Stokes equations are computed to evaluate the electroosmotic flow. The study shows that mixing efficiency can be enhanced by the combined effect of geometric modulation and surface potential heterogeneity.
Article
Biotechnology & Applied Microbiology
Lili Li, Kun Wang, Liangliang Wei, Qingliang Zhao, Huimin Zhou, Junqiu Jiang
Summary: This study investigated and optimized the mixing performance of gas and non-Newtonian fluid in high solids anaerobic digestion system using CFD simulation, exploring the impact of factors such as mixing energy magnitude, input pattern, and nozzle inlet angle on mixing effectiveness. Results showed that gas dispersed inlet achieved better mixing under specific energy conditions, emphasizing the significance of mixing performance optimization for the operation of high solids anaerobic digestion systems.
BIOCHEMICAL ENGINEERING JOURNAL
(2022)
Article
Green & Sustainable Science & Technology
Jiguang Wang, Qian Zhang, Rui Jin, Lunxiang Zhang, Yang Meng, Haiyuan Yao, Lei Yang, Jiafei Zhao, Yongchen Song
Summary: This study investigates the interaction between hydrate growth and multiphase flow through experiments. The results reveal the growth process of hydrates in dynamic systems and the corresponding flow patterns. Additionally, the feasibility of using the differential pressure method to predict hydrate blockage is explored, demonstrating its effectiveness and potential for improving transport capacity.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Thermodynamics
Jia Liu, Yi Xue, Yong Fu, Kai Yao, Jianqiang Liu
Summary: Technical advances in horizontal drilling and hydraulic fracturing have improved shale gas development, but sustainability is a challenge. Microwave irradiation can be used as an auxiliary technology for hydraulic fracturing to promote sustainable development. This study developed a fully coupled model to investigate the multiphysics coupling mechanisms and optimize recovery schemes for shale gas. The proposed model provides theoretical guidance for the field application of microwave-thermal recovery of shale gas.
Article
Mechanics
Rizwan Zahoor, Sasa Bajt, Bozidar Sarler
Summary: This numerical study evaluates the jet characteristics of non-Newtonian power-law fluids in a gas dynamic virtual nozzle. The results show that shear-thinning fluids result in thicker, longer, and slower jets compared to shear-thickening fluids. Additionally, a dripping-jetting phase diagram of the nozzle is obtained by varying the power law index, gas, and liquid flow rates.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Materials Science, Multidisciplinary
Fengsheng Qi, Shuqi Zhou, Liangyu Zhang, Zhongqiu Liu, Sherman C. P. Cheung, Baokuan Li
Summary: In this study, a three-dimensional transient mathematical model coupled with the CLSVOF method was used to analyze the mixing process under different injection flow rates and bottom-blowing positions. The results showed that as the bottom-blowing flow rate increased from 0.252 kg/s to 0.379 kg/s, the mixing time in the molten bath gradually decreased from 74 s to 66 s. When the bottom-blowing flow rate was 0.252 kg/s, it was recommended to distribute the outer bottom-blowing position on concentric circles with D-tuy,(2)/D-2 = 0.33.
Article
Mechanics
Sourabh Apte, Thibault Oujia, Keigo Matsuda, Benjamin Kadoch, Xiaoliang He, Kai Schneider
Summary: Direct numerical simulation is used to investigate the effects of turbulent flow on the transport, clustering, and deposition of fine particles in a face-centred cubic porous unit cell. The results show that particle clustering occurs at large volumes and is enhanced with increasing Stokes number.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Physics, Fluids & Plasmas
Yingying Hu, F. Romano, James B. Grotberg
Summary: We used an entropic lattice Boltzmann model to investigate the effects of surface tension on the rupture of liquid plugs in two- and three-dimensional channels. The plug's rupture was influenced by the interplay between surface tension, viscosity, and inertia. Different rupture patterns were observed depending on the plug length and channel dimensions. Increasing the wetting ability of mucus plugs could potentially aid in reopening lung airways. However, a comprehensive understanding of surface tension, viscosity, and inertia is necessary for a successful solution.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Engineering, Chemical
Carolin Kappelt, Roland Rzehak
Summary: Mass transfer in bubbly flows is of technological importance, but the modeling of mass exchange processes is less developed than momentum exchange. This study compares several proposed models for the mass transfer coefficient and evaluates them using experimental data.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Green & Sustainable Science & Technology
Haoran Wang, Makoto Ohta, Hitomi Anzai, Jiayuan Ji
Summary: This study examined the impact of different outlet diameters on biogas diffusers in Anaerobic membrane bioreactors (AnMBRs) by using computational fluid dynamics (CFD). It was found that increasing the outlet diameter improved gas velocity and wall shear stress on the membrane surface, resulting in enhanced stirring and flushing performance. However, exceeding a certain outlet diameter led to a concentrated gas distribution, which reduced the effectiveness of stirring and flushing.
Article
Engineering, Marine
Yexiang Xiao, Zhonghua Gui, Xuesong Li, Zekui Shu, Guangtai Shi, Chunwei Gu
Summary: This paper comprehensively analyzes the gas-liquid flow under different inlet gas void fractions in multiphase pumps, revealing the effect of tip leakage vortex on the gas flow pattern, and presents the characteristics of gas motion at different stages.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Review
Computer Science, Interdisciplinary Applications
Juan M. Gimenez, Sergio R. Idelsohn, Eugenio Onate, Rainald Lohner
Summary: A multiscale approach combining a novel representative volume element (RVE) with the Pseudo Direct Numerical Simulation (P-DNS) method is presented for simulating water droplets in turbulent airflow. Numerical experiments are carried out to study turbulence modulation phenomenon and a synthetic model is developed based on these experiments for global scale simulations of flows with airborne droplets via the P-DNS method. Improved predictions are obtained for flow conditions where turbulence modulation is noticeable.
ARCHIVES OF COMPUTATIONAL METHODS IN 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.