CHEMOSPHERE
·
2024
·
IF 8.1
Xu Zhang,Lixingzi Wu,Xinle Han,Yuzhi Shi,Jiwen Huang,Botao Ding,Yanhao Zhang,Zhibin Zhang,Yanfeng Shi,Fulin Li
Both perfluorooctanoic acid (PFOA) and polystyrene microplastics (PS-MPs) are emerging contaminants commonly found in aqueous environments. In co-contaminated areas, MPs may act as carriers for PFOA, complicating transport dynamics. However, information on their cotransport in porous media is limited. This study investigates the transport behaviors of PFOA and PS-MPs in saturated quartz sand columns under varying ionic strength (IS), cation type, and pH. Using the DLVO interaction energy theory and a mathematical model, we analyzed their cotransport. The results demonstrated that PS-MPs inhibited PFOA transport due to hydrophobic adsorption, reducing PFOA mobility. However, at pH 5, PS-MPs facilitated PFOA transport through competitive adsorption on sand surfaces. Conversely, PFOA significantly accelerated PS-MPs transport, likely due to electrostatic repulsion and reduced PS-MPs size. The promoting effect of PFOA on PS-MPs was similar in NaCl and CaCl 2 solutions. It is noteworthy that under acidic conditions, the increased electrostatic attraction between PS-MPs and quartz sand leads to substantial adsorption of PS-MPs onto the quartz sand surface. Under these conditions, PFOA exerts almost no promoting effect on PS-MPs. This study showed that the coexistence of PS-MPs and PFOA would influence the mobility of each other in the saturated porous media. Overall, the findings from this work could greatly improve our understanding of cotransport behaviors and environmental risk of PS-MPs and PFOA.
研究领域:
环境科学
·
污染生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Sciences
·
2016
·
IF 2.208
Lixin Wang,Xuezhi Yang,Qi Wang,Yuxuan Zeng,Lei Ding,Wei Jiang
The aggregation and deposition of carbon nanotubes (CNTs) determines their transport and fate in natural waters. Therefore, the aggregation kinetics of humic-acid treated multi-walled carbon nanotubes (HA-MWCNTs) was investigated by time-resolved dynamic light scattering in NaCl and CaCl 2 electrolyte solutions. Increased ionic strength induced HA-MWCNT aggregation due to the less negative zeta potential and the reduced electrostatic repulsion. The critical coagulation concentration (CCC) values of HA-MWCNTs were 80 mmol/L in NaCl and 1.3 mmol/L in CaCl 2 electrolyte, showing that Ca 2 + causes more serious aggregation than Na + . The aggregation behavior of HA-MWCNTs was consistent with Derjaguin–Landau–Verwey–Overbeek theory. The deposition kinetics of HA-MWCNTs was measured by the optical absorbance at 800 nm. The critical deposition concentrations for HA-MWCNT in NaCl and CaCl 2 solutions were close to the CCC values, therefore the rate of deposition cannot be increased by changing the ionic strength in the diffusion-limited aggregation regime. The deposition process was correlated to the aggregation since larger aggregates increased gravitational deposition and decreased random Brownian diffusion. HA-MWCNTs hydrodynamic diameters were evaluated at 5, 15 and 25°C. Higher temperature caused faster aggregation due to the reduced electrostatic repulsion and increased random Brownian motion and collision frequency. HA-MWCNTs aggregate faster at higher temperature in either NaCl or CaCl 2 electrolyte due to the decreased electrostatic repulsion and increased random Brownian motion. Our results suggest that CNT aggregation and deposition are two correlated processes governed by the electrolyte, and CNT transport is favored at low ionic strength and low temperature.
研究领域:
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Minfei Jian,Jiarui Niu,Wenhua Li,Yuyue Huang,Hao Yu,Zheng Lai,Shuli Liu,Elvis Genbo Xu
Microplastics (MPs) are widely detected in wetlands as emerging pollutants of global concern. Co-occurrence of MPs and trace metals in wetlands is common and the vector effects of MPs on other environmental pollutants have been increasingly reported. However, the interaction of different MPs and trace metals under environmentally realistic conditions is not well understood. Here, we investigated the adsorption capacity of MPs for metals under simulated conditions of Poyang Lake wetlands in Jiang Xi, China, a Ramsar site of international importance for conservation and sustainable use. ICP-MS was used to quantify the amount of adsorbed metals onto different types of MPs. SEM-EDS and micro-FTIR were used to examine the morphological and chemical characteristics of MPs before and after metal adsorption. The influence of internal (polymer types and particle sizes of MPs) and external factors (water pH values, organic matters, ion strength, and sediment) on metal adsorption was systematically investigated. Metal adsorption equilibrium was most achieved at 72 h. The adsorption capacity of MP types to metal ions tended to decrease as PP > PE > PS, and the amount of adsorbed metals decreased as Cu > Pb > Cd. The amount of adsorbed metals generally decreased with the increase of particle size of MPs. With the increase of water pH and K + strength, the adsorption of metals by MPs showed an increasing and then decreasing trend; the adsorption capacity of MPs increased with the increase of fulvic acid. Under the simulated sedimentary conditions, the adsorption of different metals by MPs also tended to be Cu > Pb > Cd, which was mainly determined by metal concentrations in the sediments collected in situ . The results of this study improve our understanding of metal-MP interaction under simulated environmental conditions, shedding new light on the environmental behavior of MPs and metals in wetlands.
研究领域:
环境科学
·
生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2021
·Vol. 10
·期 8
·1868
·
IF 4.35
Huanhuan Cui,Qihang Liu,David Julian McClements,Bin Li,Shilin Liu,Yan Li
Protein-stabilized emulsions tend to be susceptible to droplet aggregation in the presence of high ionic strengths or when exposed to acidic gastric conditions due to a reduction of the electrostatic repulsion between the protein-coated droplets. Previously, we found that incorporating cinnamaldehyde into the oil phase improved the resistance of whey protein isolate (WPI)-stabilized emulsions against aggregation induced by NaCl, KCl and CaCl2. In the current study, we aimed to establish the impact of cinnamaldehyde on the tolerance of WPI-stabilized emulsions to high salt levels during food processing and to gastric conditions. In the absence of cinnamaldehyde, the addition of high levels of monovalent ions (NaCl and KCl) to WPI-emulsions cause appreciable droplet aggregation, with the particle sizes increasing from 150 nm to 413 nm and 906 nm in the presence of NaCl and KCl, respectively. In contrast, in the presence of 30% cinnamaldehyde in the oil phase, the WPI-emulsions remained stable to aggregation and the particle size of emulsions kept within 200 nm over a wide range of salt concentrations (0–2000 mM). Divalent counter-ions promoted droplet aggregation at lower concentrations (≤20 mM) than monovalent ones, which was attributed to ion-binding and ion-bridging effects, but the salt stability of the WPI emulsions was still improved after cinnamaldehyde addition. The incorporation of cinnamaldehyde into the oil phase also improved the resistance of the WPI-coated oil droplets to aggregation in simulated gastric fluids (pH 3.1–3.3). This study provides a novel way of improving the resistance of whey-protein-stabilized emulsions to aggregation at high ionic strengths or under gastric conditions.Keywords:whey protein;stability;ionic strength;gastric digestion;emulsions
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYST
·
2015
·Vol. 140
·期 10
·3368-3374
·
IF 4.107
Yan-Ran Li,Ye Sun,He-Fang Wang
Convenient reading out and/or determination of ionic strength (IS) is of great significance for both scientific research and real life applications. We presented here a novel method for the rapid and sensitive IS assay based on the electrolyte-induced sensitive wavelength blueshifts of the reflection spectra of polyacrylate capped Fe3O4 magnetic photonic crystals (PA–Fe3O4-MPCs). For HCl, MgSO4 and the common electrolytes corresponding to the salinity of seawater (including NaCl, KCl, MgCl2, CaCl2, Na2SO4 and their mixtures), the PA–Fe3O4-MPCs displayed wavelength blueshifts identical to the total IS of the aqueous solutions, regardless of the kind of above-mentioned electrolytes in the solutions. Besides, the PA–Fe3O4-MPCs exhibited relatively high sensitivity (an average of 294 nm L mmol−1 in the range of 0.05–0.30 mmol L−1, and an even higher value of 386 nm L mmol−1 at 0.05–0.15 mmol L−1) and fast response (within 8 s) to the IS of aqueous solutions. The relative standard deviation (RSD) for IS (NaCl, 0.1 mmol L−1) was 4.4% (n = 5). The developed method was applied to determine the salinity of seawater samples, and the determined results were validated by the traditional standard chlorinity titration and electric conductimetry method. The recoveries were in the range of 92–104%. The proposed PA–Fe3O4-MPCs based reflectometry method would have great potential for IS and salinity assays.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2021
·Vol. 17
·期 1
·e2720
·
IF 1.447
Chao Jia,Hu Shen,Yingyu Xu,Xingbang Hu,Guoqiang Yang,Zhibing Zhang
With enormous interfacial area for particle collection, microbubbles exhibit great application prospect in the mineral flotation. Under certain ionic strength, microbubbles can be produced continuously in the microbubble column without extra reagent addition. In this work, multiphase flow characteristics (Sauter mean diameter, bubble size distribution, gas holdup & interfacial area) were studied systematically with variables including the salt type, salt concentration, and operating conditions. Based on mathematical model, critical coalescence concentration was determined for each investigated salt. According to experimental results, a mathematical correlation was established between the Sauter mean diameter and ionic strength. For the formation of microbubble system, the lowest ionic strength was approximately 0.5 mol/L. Multiphase flow characteristics in the microbubble column depended highly on the ionic strength. The interfacial area and gas holdup increased by 38 times and more than 3 times respectively, with the ionic strength of Al 2 (SO 4 ) 3 rising from 0 to 1.5 mol/L. The critical coalescence concentration ranged from 0.037 mol/L (Al 2 (SO 4 ) 3 ) to 0.517 mol/L (NaCl), which correlated with the ionic strength of each salt.
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
DOI
高影响因子
ACS Nano
·
2022
·
IF 18.027
Hui Chen,Yibin Wang,Yuezhen Liu,Qian Zou,Jiangfan Yu
Sensing of key parameters in fluidic environments has attracted extensive attention because the physical features of body fluids could be used for point-of-care disease diagnosis. Although various sensing methods have been investigated, effective sensing strategies of microenvironments remains a major challenge. In this paper, we propose an approach that can realize sensing of fluidic viscosity and ionic strength using microswarms formed by simple colloidal nanoparticles. The influences of fluidic ionic strength and viscosity on two swarm behaviors are analyzed (i.e., the spreading of circular vortex-like swarms and the elongation of elliptical swarms). The data models for quantifying the fluidic viscosity and ionic strength are obtained from experiments, and the fluidic features can be sensed successfully using the swarm behaviors. Furthermore, we demonstrate that the microswarms have the capability of passing through tortuous and narrow microchannels for sensing. Continuous sensing of different fluidic environments using swarms is also realized. Finally, the sensing of viscosity and ionic strength of porcine whole blood is presented, which also validates the feasibility of the sensing strategy.
研究领域:
生物医学工程
·
纳米技术
·
诊断学
✓ 已验证
DOI
PubMed
高影响因子
Environmental Pollutants and Bioavailability
·
2021
·
IF 1.737
Younan Zhao,Yanji Jiang,Runfeng Kang,Menghua Chen,Zhe Zhang,Huimin Sun,Nong Wang
The presence of different soils composition complicates the transport behaviors of Cd(II) and thus makes it challenging to predict Cd(II) fate and transport. In this study, montmorillonite modified sand, humic acid modified sand and ferrihydrite modified sand were used as medium to explore the effect of modified sand content, pH and ionic strength (IS) on Cd(II) transport. The results revealed that the adsorption capacity of modified sand for Cd(II) was montmorillonite-coated sand>humic acid-coated sand>ferrihydrite-coated sand>quartz sand. While the increase of the coated sand content limited the transport ability of Cd(II) in sand columns. In addition, high IS and low pH promoted the mobility of Cd(II). The specific surface area, surface charge and adsorption sites of coated sand were the factors affecting the transport of Cd(II). This work provides new information on the transport and spread of Cd(II) in the soil and thus to better prevent Cd(II) from polluting the environment.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Shu-Cui Ma,Ji-Lin Zhang,De-Hui Sun,Gui-Xia Liu
Removal of noxious heavy metal ions (e.g. Pb(II)) by surface adsorption of minerals (e.g. diatomite) is an important means in the environmental aqueous pollution control. Thus, it is very essential to understand the surface adsorptive behavior and mechanism. In this work, the Pb(II) apparent surface complexation reaction equilibrium constants on the calcined diatomite and distributions of Pb(II) surface species were investigated through modeling calculations of Pb(II) based on diffuse double layer model (DLM) with three amphoteric sites. Batch experiments were used to study the adsorption of Pb(II) onto the calcined diatomite as a function of pH (3.0–7.0) and different ionic strengths (0.05 and 0.1 mol L −1 NaCl) under ambient atmosphere. Adsorption of Pb(II) can be well described by Freundlich isotherm models. The apparent surface complexation equilibrium constants (log K ) were obtained by fitting the batch experimental data using the PEST 13.0 together with PHREEQC 3.1.2 codes and there is good agreement between measured and predicted data. Distribution of Pb(II) surface species on the diatomite calculated by PHREEQC 3.1.2 program indicates that the impurity cations (e.g. Al 3+ , Fe 3+ , etc.) in the diatomite play a leading role in the Pb(II) adsorption and dominant formation of complexes and additional electrostatic interaction are the main adsorption mechanism of Pb(II) on the diatomite under weak acidic conditions.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Agronomy-Basel
·
2024
·Vol. 14
·期 2
·352
·
IF 3.3
Zihao Ye,Dihao Xu,Jiawen Zhong,Shuang Gao,Jinjin Wang,Yulong Zhang,Huijuan Xu,Yongtao Li,Wenyan Li
The co-transport of contaminants by soil colloids can generate substantial environmental risk, and this behavior is greatly affected by environmental conditions. In this study, AF4-ICP-MS was used to investigate the size distribution and composition of Cd/Pb-bearing colloids; saturated sand column experiments were used to investigate the impact of soil colloids on the transport of Cd/Pb under different pH and ionic strength conditions. AF4-ICP-MS characterization showed that natural colloids were primarily associated with two sizes ranges: 0.3–35 KDa (F1, fine nanoparticles) and 280 KDa–450 nm (F2, larger nanoparticles), which mainly consisted of organic matter (OM), iron (Fe), and manganese (Mn) (oxy)hydroxides and clay minerals. Fine nanoparticles could strongly adsorb Cd and Pb under all environmental conditions. Mn and Fe (oxy)hydroxides generally formed under neutral to alkaline conditions and exhibited adsorption capabilities for Cd and Pb, respectively. Transport experiments were conducted under different pH and ionic strength conditions. At pH 3.0, soil colloids had little effect on the transport of Cd2+and Pb2+. At pH 5.0, soil colloids inhibited the transport of Cd2+by 16.1%, and Pb2+recovery was still 0.0%. At pH 7.0 and 9.0, soil colloids facilitated the transport of Cd2+by 15.6% and 29.6%, facilitated Pb2+by 1.3% and 6.4%. At an ionic strength of 0, 0.005, and 0.01 mol L−1NaNO3, soil colloids facilitated the transport of Cd2+by 77.7%, 45.8%, and 15.6%, only facilitated the transport of Pb2+by 46.2% at an ionic strength of 0 mol L−1NaNO3. At an ionic strength of 0.05 mol L−1NaNO3, soil colloids inhibited the transport of Cd2+and Pb2+by 33.1% and 21.0%, respectively. The transport of Cd2+and Pb2+facilitated by soil colloids was clearly observed under low ionic strength and non-acidic conditions, which can generate a potential environmental risk.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 45
·39131-39136
·
IF 3.289
Kai Qin,Yani Yan,Yahong Zhang,Yi Tang
Cellulose without any pretreatment was directly converted into levulinic acid (LA) in a microwave-assisted acidic catalytic system with a high ionic strength. The highest LA yield could reach 67.3 mol% within 60 min even when the cellulose concentration was as high as 10 wt%. It is concluded that high ion strength and microwave irradiation were jointly responsible for the fast cellulose conversion and high LA yield, and a cooperative acceleration mechanism is finally proposed. The high ion concentration provided by alkali metal halides not only accelerated the cellulose hydrolysis but also facilitated glucose conversion into LA by shifting the weak acid ionization equilibria, and microwave irradiation further promoted this salt effect by its characteristic heating way of ion conduction. Such a one-pot catalytic system provides a possibility of practical application for direct highly efficient conversion of cellulose due to its green properties, low cost and efficient characteristics.
研究领域:
生物化学
·
可再生资源工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2022
·
IF 9.988
Zongrui Li,Shengsheng Li,Liangzhong Li,Lin Tao,Xiaohui Zhu,Ruixue Ma,Bingbing Sun,Yanhong Zhang,Yunjiang Yu
The presence of microplastics (MPs) and the associated organic pollutants in the aquatic environment has attracted growing concern in recent years. MPs could compete with chemicals for adsorption sites on the surface of sediment, affecting the sorption processes of pollutants on sediment. However, few studies focused on the binary system of microplastics-sediment (MPs-S), which appear much common in aquatic environment. Herein, we investigated the interactions between a continuously used flame retardant tetrabromobisphenol A (TBBPA) and four MPs-S complexes (PVC–S, PE-S, PP-S and PS-S). The equilibrium adsorption capacities were 17.1, 15.6, 15.4, and 14.0 mg/kg for PVC-S, PS-S, PE-S, and PP-S, respectively. Kinetics suggest that adsorption behavior of TBBPA was fitted by pseudo-second-order model. Co-adsorption of TBBPA in binary systems were much lower than the sum of each simple system, which may be due to the mutually occupied adsorption sites. Higher ionic strength and lower dissolved organic matter strengthened the sorption of TBBPA onto MPs-S complexes. The enhanced sorption capacities for TBBPA were observed with elevated proportion and small particle size of MPs in the MPs-S complexes. This study contributes to the knowledge on the impact of MPs in partitioning of organic pollutants in-between solid and aqueous phases in the aquatic environment.
研究领域:
环境科学
·
污染生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）