ENVIRONMENTAL POLLUTION
·
2019
·
IF 5.714
Yunqi Qin,Zong Wen,Wenjing Zhang,Juanfen Chai,Dan Liu,Shengyu Wu
Because of the complexity of contaminants infiltrating groundwater, it is necessary to study the co-transport of contaminants in the vadose and saturated zones . To investigate the role of inorganic colloids in the transport of biocolloids through porous media, a series of experiments were performed using columns packed with sand. The Escherichia coli phage ( E. coli phage) was used as the model virus and silica as the model colloid in this study. The model virus exhibited a higher degree of attachment when compared with silica under similar experimental conditions. Under unsaturated flow conditions, the degree of virus retention was higher than in the corresponding saturated flow case, regardless of the presence of silica. Mass recovery and breakthrough curve data showed that silica hindered virus transport in saturated porous media. The model virus exhibited a higher degree of retention in the presence of silica. This could be related to pore structure changes caused by aggregated virus-silica particles located within the pores of the sand. Conversely, the suspended virus retained at the air-water interface provided new retention sites for other colloids; the retention was observed to be higher in the presence of colloidal silica in the saturated columns. In the corresponding unsaturated experiments, silica was observed to play the opposite function with respect to virus transport, which demonstrated that silica facilitated virus transport in the presence of unsaturated porous media. Capillary forces were stronger than the virus-silica interactions, and inhibited the aggregation of particles . Suspended silica competes with the virus for sorption sites because of a high affinity for the air-water interface. This competition inhibits virus retention by electrostatic repulsion of like-charged particles, and concomitantly facilitates virus transport under unsaturated conditions .
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
CHEMICAL SPECIATION AND BIOAVAILABILITY
·
2018
·
IF 1.362
Bingyi Xie,Yanji Jiang,Zhe Zhang,Gang Cao,Huimin Sun,Nong Wang,Shengsen Wang
The transport of Pb(II) or Cd(II) in subsurface has been studied in the literature; however; their co-transport in porous media in presence of colloids has not been clearly understood. In this work, a series of column experiments were conducted to study Pb(II) and Cd(II) co-transport in saturated porous media under various experimental conditions with different combination of colloidal solution (montmorillonite colloid, manual loessial soil colloid and humic acid), flow rate (0.1, 0.5 and 1.0 ml min−1) and sand grain size (0.4–0.8mm and 0.8–2.0mm). The results showed that increase of flow rate and grain size promoted the mobility of Pb(II) and Cd(II), furthermore, the presences of mobile colloids also enhanced the mobility of the two heavy metals, meanwhile, Cd(II) showed higher mobility than Pb(II) in the columns. Findings from this work enhanced current understanding of the competitive transport and colloid-facilitated transport of heavy metals in saturated porous media.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2018
·
IF 4.968
Akram Entezari,T.S. Ge,R.Z. Wang
The desiccants made by confined salt in a porous matrix (CSPM) were proposed in the 1990s. Profiting off of a high sorption capacity and a low regeneration temperature made this field very interesting research topic. In absorption refrigeration cycles , adopting multi salts has been investigated widely. LiCl and LiBr are known for their high water adsorption capacity . The combinations of these two salts might be a tool for an intentional modification of CSPMs too. In this study, different ratios of these two salts were impregnated into silica gel pores. The textural properties, water sorption isotherms, and kinetics were analyzed. Four mathematical models were applied for estimating dynamic sorption coefficients. SIM and LDF were well-fitted to describe kinetics. The results showed that impregnated salts molar ratios affect the sorption characteristics. Adding a small amount of LiBr to the LiCl composites intensifies the sorption capacity up to 5.5% while adding LiCl to LiBr decrease this parameter by 12.7%. Besides, a mathematical simulation was used to estimate their performance in a real desiccant cooling heat exchanger . For a standard cooling and dehumidification conditions, the simulation results showed that the binary salt composites might improve the dehumidification if a proper salts ratio was selected.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Processes & Impacts
·
2024
·
IF 4.3
Chang Xu,Bo Gong,Shan Zhao,Xiao-Min Sun,Shu-Guang Wang,Chao Song
Tetracycline (TC) and Cu(II) coexist commonly in various waters, which may infiltrate into the subterranean environment through runoff and leaching, resulting in substantial ecological risks. However, the underlying mechanisms why Cu(II) affects the transport of TC in porous media remain to be further explored and supported by more evidence, especially the role of complexation. In this study, the transport of TC with coexisting Cu(II) was comprehensively explored with column experiments and density functional theory (DFT) calculation. At natural environmental concentrations, Cu(II) significantly inhibited the transport of TC in the quartz sand column. Cu(II) augmented the retention of TC in the column mainly via electrostatic force and complexation. The interaction between TC and TC–Cu complexes on the surface of SiO2 was investigated with first-principles calculations for the first time. There were strong van der Waals forces and coordination bonds on the surface of complexes and SiO2, leading to higher adsorption energy than that of TC and inhibiting its penetration. This study offers novel insights and theoretical framework for the transport of antibiotics in the presence of metal ions to better understand the fate of antibiotics in nature.
研究领域:
环境科学
·
理论化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOILS AND SEDIMENTS
·
2019
·Vol. 20
·期 2
·911-920
·
IF 2.669
Zhang Mo,Li Duo,Ye Zhi,Wang Shiqi,Xu Nan,Wang Fang,Liu Shouqing,Chen Jianping,Gu Huajie
Purpose Nano silicon particles (nSiO 2 ) is one of the most widely used industrial engineered nanomaterials (ENMs). The extensive applications of nSiO 2 may pose potential risks to aquatic ecosystems and human health. Humic acid (HA) is a major component of soil and water that exists widely in the natural environment and adsorbs to the surface of nanoparticles, which affects the fate and transport of ENMs in soil. Therefore, it triggers the necessity to study the chemical reaction of HA controlling the sedimentation and transport of nSiO 2 . Materials and methods The sedimentation kinetics and transport breakthrough curves of nSiO 2 with/without HA in water-saturated porous media were studied in two electrolyte (NaCl and CaCl 2 ) solutions. The likely mechanisms were explored with both multiple technologies and numerical modeling including TEM-EDX, particle size distribution, zeta potentials, and the two-site kinetic attachment model (TSKAM). Results and discussion Our experimental results showed that the existence of HA generally increased the suspensivity and the transportability of nSiO 2 in NaCl and CaCl 2 solutions in packed sand columns at acidic pH. This result was attributed to the HA adsorption leading to the more negatively charged surface and the smaller size of nSiO 2 aggregates. However, the formation of coordination complexes associated with larger cluster among nSiO 2 between HA and Ca 2+ contributed to the increased sedimentation of nSiO 2 at alkaline pH. Subsequently, the presence of HA inhibited the transport of nSiO 2 in CaCl 2 solution at pH 9.0. Comparably, in NaCl at pH 9.0, HA showed the negligible effect on the nSiO 2 deposition in sand. Both the attachment and detachment parameters, which were obtained from fitting the breakthrough curves of ENMs using the TSKAM, could be used to well describe the transport behavior of nSiO 2 with HA under various conditions. In particular, the irreversible attachment parameters at site 2 on sand were positively related to the retention of nSiO 2 with HA. Conclusions The fate and transport of nSiO 2 can be distinctly affected by HA depending on the ion composition, ion strength, and pH in soil. This study will provide insights for assessing the mobility of nSiO 2 with HA in subsurface soil and aquatic environments.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 53
·80693-80704
·
IF 5.19
Wei Qiqi,Chen Jiuyan,Zhang Qiang,Lu Taotao,Farooq Usman,Chen Weifeng,Qi Zhichong
Colloid-mediated contaminant mobility is absolutely critical for the environmental behavior of contaminants such as antibiotics in water resources. In this study, the influences of phosphate (a commonly inorganic ligand in the environment) on the ferrihydrite colloid-mediated transport of tetracycline (TC, a typical antibiotic) in porous media were investigated. In the absence of colloids, phosphate promoted TC mobility due to the competitive deposition of phosphate and TC on the sand surface as well as the electrostatic repulsion. Interestingly, ferrihydrite colloids could inhibit TC transport; however, the inhibitory effect of the colloids was weakened by the addition of phosphate. This phenomenon stemmed from colloid-associated TC mobility, the increased electrostatic repulsion induced by adsorbed phosphate, and deposition site competition effect. Another interesting finding was that the impacts of phosphate on the colloid-mediated mobility of TC were pH-dependent. That is, phosphate exhibited a weaker effect on the inhibitory role of ferrihydrite colloids in TC mobility at pH 5.0 than that at pH 7.0; specially, ferrihydrite colloids acted as possible carriers of TC and facilitated antibiotic transport at pH 9.0. The observations were ascribed to different influences of phosphate on the binding affinity of ferrihydrite toward TC and the mobility of free TC under different pH conditions. Therefore, the findings of this study provide useful information about the fate and co-transport of antibiotics and natural mineral colloids in the presence of inorganic ligands in the aquatic environment.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
ACS Omega
·
2022
·
IF 4.132
Xiaoxiao Dou,Zhewen Chen,Xiaojian Cao,Chicheng Ma,Jianlin Liu
Magnetic fluid is a new type of smart material, which holds implications for highly enhancing the oil displacement efficiency. In the present study, we perform a comprehensive investigation to probe the influence of a magnetic fluid on the displacement efficiency in porous media under the action of magnetic force. First, the displacement efficiency is measured by a self-developed setup, where factors such as the magnet thicknesses, the volume of the fluid injected, the fluid injection speed, and the porosity of the sample are surveyed as controllable variables. Moreover, the experimental results are well verified by the scaling laws according to the principle of dimensional balance. Next, a numerical simulation is performed to explore the detailed displacement process. First, the magnetic force generated by the ring magnet is calculated. Then, the function curves of the displacement efficiency with respect to the controlling variables are validated by the numerical simulation. In addition, the numerical simulation also demonstrates the volume phase distribution, the pressure field, and the velocity field of the mixed fluid during the displacement process. The simulation results are in excellent agreement with the experimental data. These findings are beneficial for us to better understand the oil displacement with the aid of external fields, which also provide inspiration for the areas of microfluidics, diffusion of pollutants, microsensors, etc.
研究领域:
石油工程
·
材料科学
·
流体力学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Fei Wang,Jiuyan Chen,Yalei Xu,Usman Farooq,Taotao Lu,Weifeng Chen,Xinhai Wang,Zhichong Qi
Knowledge of the mobility of tetracycline (TC) antibiotics in porous media is critical to understand their potential environmental influences. The transport characteristics of TC in sand columns with three different surfactants, including Tween 80, sodium dodecylbenzene sulfonate (SDBS), and didodecyldimethylammonium bromide (DDAB) under various conditions were investigated in this study. Results demonstrated that all surfactants enhanced TC transport under neutral conditions (10 mM NaCl at pH 7.0). The observation was attributed mostly to deposition site competition, higher electrostatic repulsion between TC molecules and sand grains, steric hindrance, and the increase of TC hydrophilicity. Furthermore, the order of the transport-enhancement effects was generally observed as follows: DDAB > SDBS > Tween 80. The trend was controlled by the variation in the physicochemical properties of surfactants. It was noticed that the presence of Cu 2+ (a model divalent cation) in the background solution, the cation-bridging contributed to the promotion effects of DDAB or Tween 80 on TC mobility. Interestingly, SDBS considerably suppressed TC transport due to the precipitation of SDBS–Cu 2+ complexes onto sand surfaces. Moreover, the enhancement order of surfactants at pH 5.0 was similar to that pH 7.0. However, DDAB could inhibit TC transport in sand columns at pH 9.0, which were mainly caused by the decrease of electrostatic repulsion and the hydrophobicity induced by the binding cationic surfactant. Findings from this work provide novel insight into involvement of surfactants in antibiotic transport behaviors in the subsurface environment.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
Entropy
·
2023
·Vol. 25
·期 2
·278
·
IF 2.7
Kefeng Yan,Jianyu Zhao,Xiaosen Li,Jingchun Feng,Zhiming Xia,Xuke Ruan
The swelling characteristics of porous media in the offshore natural gas hydrate reservoir have an important effect on the stability of the reservoir. In this work, the physical property and the swelling of porous media in the offshore natural gas hydrate reservoir were measured. The results show that the swelling characteristics of the offshore natural gas hydrate reservoir are influenced by the coupling of the montmorillonite content and the salt ion concentration. The swelling rate of porous media is directly proportionate to water content and the initial porosity, and inversely proportionate to salinity. Compared with water content and salinity, the initial porosity has much obvious influence on the swelling, which the swelling strain of porous media with the initial porosity of 30% is three times more than that of montmorillonite with the initial porosity of 60%. Salt ions mainly affect the swelling of water bound by porous media. Then, the influence mechanism of the swelling characteristics of porous media on the structural characteristics of reservoir was tentatively explored. It can provide a basic date and scientific basis for furthering the mechanical characteristics of the reservoir in the hydrate exploitation in the offshore gas hydrate reservoir.Keywords:natural gas hydrate;porous media;swelling characteristics;structural characteristics
研究领域:
地质学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2022
·
IF 8.035
Xin Chen,Yiqiang Li,Zheyu Liu,Jian Zhang,Japan Trivedi,Xianjie Li
Particle migration in porous media is of great significance in the areas of formation-water filtration and oil field development. The current theories and methods ignore the effect of particle elasticity on its flow resistance, which is the key point for particle parameters design toward reservoir profile control. Therefore, this paper focuses on the research on the migration process and flow resistance prediction of elastic particles in porous media. Based on the Hertzian contact theory, a migration and plugging model of the elastic particle in porous media is established. Then, core slice injection and microfluidic experiments were used to study the migration process of particles in porous media, which can provide an accurate coefficient for the migration and plugging model. And long core injection experiments were carried out using three kinds of elastic particles (3.7 μm, 8.4 μm, and 21.1 μm) to verify the accuracy of the model. The results show that elastic particles will form a filter cake within 3 cm of the injection end of the core. Combined with the microfluidic visualization experiment, the transport process of elastic particles in porous media can be summarized as the “Gathered and Energized” transport mode with three stages: particles accumulate at the injection end and increase the injection pressure, particles squeeze into the core, and particles deep migration. The migration and plugging model of elastic particles can predict its injection pressure in porous media, which is highly consistent with the experimental data, with an average error of 8.4%. When the reservoir permeability is constant, the injection pressure of elastic particles changes exponentially with the matching factor. In addition, the reservoir permeability also directly affects the injection pressure of elastic particles. When the permeability increases from 1.7 D to 6.0 D, the injection pressure decreases by >70%. This model provides a new method to study the migration of elastic particles in porous media and predict the flow resistance, which is of guiding significance to the bilateral matching design of elastic particles and reservoirs.
研究领域:
石油工程
·
力学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 48
·105247-105258
·
IF 5.8
Chen Yuzhen,Tan Yan,Su Lezhu,Zou Wangqi,Wu Binhai,Gao Wenbin,Hu Zhan,Li Aoxuan,Zhou Zhi,Zhou Nan
At present, studies on biochar transport have focused on biochar obtained by oxygen-limited pyrolysis, which may differ from conventional biochar produced by incineration in nature. This work investigated the transport and retention mechanisms of three types of oxygen-limited pyrolytic biochar and three types of traditional biochar in saturated porous media. The results showed that the specific surface area of the three oxygen-limited pyrolysis biochar (180–200 m 2 ·g −1 ) was higher than that of the traditional biochar (50–60 m 2 ·g −1 ). Therefore, the retention capacity of pyrolytic biochar is strong and the permeability is less than 0.1. The absolute value of the zeta potential of traditional biochar is greater than 30 mV, and the electrostatic repulsion generated is stronger, with a peak penetration rate of 0.16. Moreover, the zeta potential of biochar and traditional biochar is regulated by pH value and ionic strength. In acidic conditions or solutions with high ionic strength, the zeta potentials of the six types of biochar changed to about − 15 mV, and the second minimum value was less than 0, indicating that there was a tendency for sedimentation. This study provides a new perspective for assessing the transport and environmental risks of biochar in the environment.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2025
·
IF 5.3
Minghang Mao,Kefeng Yan,Chang Chen,Xiaosen Li,Zhaoyang Chen,Gang Li,Yi Wang
As a new type of clean energy, the exploitation of natural gas hydrate resources is key in global energy development of the future. A fundamental understanding of the heat transfer characteristics of natural gas hydrate reservoirs is critical for effective natural gas hydrate exploitation. In this work, the heat transfer characteristics of the sediments on marine natural gas hydrate reservoirs were investigated by using experiments and machine learning algorithms. The thermal conductivities of natural marine sediments from the marine natural gas hydrate reservoir and their primary porous media (quartz sand, Illite, and montmorillonite) were measured. The effects of the porous media component, the water content, the salt concentration, and the phase state change on the thermal conductivity of the reservoir were discussed. The experimental results show that the thermal conductivity of the reservoir depends not only on the inherent thermal conductivity of the porous media but also on the heat transfer mode between the components. The effective thermal conductivity of the porous media system is proportional to the water content and inversely proportional to the salt concentration in porous media. The swelling characteristics of porous media affect the heat transfer mode of the system, thus affecting the extent of change in the effective thermal conductivity with variations in the water content and salt concentration. During the phase transition process, the swelling characteristics of the porous media slow down the heat transfer process, an effect that can be mitigated by the swelling inhibition caused by salt. Additionally, the performances of six machine learning algorithms were evaluated using four evaluation indicators. Results show that the gradient boosted decision trees (GBDT) can yield good predicted values of the thermal conductivity of porous media in a marine natural gas hydrate. A feature importance analysis further reveals that the salt concentration and porous media components are the essential factors influencing the thermal conductivity of marine gas hydrate reservoirs.
研究领域:
能源地质学
·
机器学习应用
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）