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Li Z, Hu Y, Chen Y, Fang S, Liu Y, Tang W, Chen J. Reciprocal effects of NOM and solution electrolyte ions on aggregation of ferrihydrite nanoparticles. CHEMOSPHERE 2023; 332:138918. [PMID: 37178934 DOI: 10.1016/j.chemosphere.2023.138918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 05/04/2023] [Accepted: 05/10/2023] [Indexed: 05/15/2023]
Abstract
The effects of natural organic matter (NOM) types and electrolyte ions are crucial to the aggregation of ferrihydrite nanoparticles (Fh NPs) in the environment. Dynamic light scattering (DLS) was employed for the aggregation kinetics of Fh NPs (10 mg/L as Fe) in the present study. The critical coagulation concentration (CCC) values of Fh NPs aggregation in NaCl were obtained in the presence of 15 mg C/L NOM as SRHA (857.4 mM) > PPHA (752.3 mM) > SRFA > (420.1 mM) > ESHA (141.0 mM) > NOM-free (125.3 mM), indicating Fh NPs aggregation was inhibited as the above order. Comparatively in CaCl2, the CCC values were measured in ESHA (0.9 mM), PPHA (2.7 mM), SRFA (3.6 mM), SRHA (5.9 mM), NOM-free (76.6 mM), implying NPs aggregation was enhanced following the order of ESHA > PPHA > SRFA > SRHA. To investigate the dominant mechanisms, the aggregation of Fh NPs was comprehensively studied under the effects of NOM types, concentrations (0-15 mg C/L) and electrolyte ions (NaCl/CaCl2 beyond CCC). In NaCl/CaCl2, the low concentration of NOM (<7.5 mg C/L) could accelerate NPs aggregation mainly due to patch-charge attraction. When NOM concentration was high (>7.5 mg C/L), the inhibition effect on NPs aggregation occurred in NaCl due to steric repulsion, whereas the enhancement effect in CaCl2 of aggregation was dominated by the bridging effect. The results indicated that the effects of NOM types, concentration and electrolyte ions should be carefully considered for the environmental behavior of NPs.
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Affiliation(s)
- Zhixiong Li
- State Key Laboratory of Biogeology & Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China
| | - Yandi Hu
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China; State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing, 100871, PR China
| | - Yufan Chen
- State Key Laboratory of Biogeology & Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China
| | - Shiyu Fang
- State Key Laboratory of Biogeology & Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China
| | - Yuyan Liu
- State Key Laboratory of Biogeology & Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China
| | - Wei Tang
- State Key Laboratory of Biogeology & Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China
| | - Jiawei Chen
- State Key Laboratory of Biogeology & Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China.
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2
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Liu B, Guo C, Ke C, Chen K, Dang Z. Colloidal stability and aggregation behavior of CdS colloids in aquatic systems: Effects of macromolecules, cations, and pH. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161814. [PMID: 36708836 DOI: 10.1016/j.scitotenv.2023.161814] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 06/18/2023]
Abstract
Redox-dynamic environments such as river floodplains and paddy fields have been demonstrated to be important sources of CdS colloids. To date, the aggregation kinetics of CdS colloids had not yet been studied, and the structure and properties of macromolecules on the interaction between different macromolecules and CdS colloids, as well as the aggregation behavior of CdS colloids are unclear. This study investigated the colloidal stability of CdS colloids in model aqueous systems with various solution chemistry and representative of macromolecules. The results showed that increased electrolyte concentration destabilized CdS colloids by charge screening, with the cationic effect following Ca2+ > Mg2+ > K+ > Na+; Higher solution pH stabilized CdS colloids by raising the critical coagulation concentration from 33 to 56 mM NaCl. Electron microscopy and spectroscopy verified the strong interaction between macromolecules and CdS colloids, and macromolecule adsorbed on the surface of CdS to form a protective layer called "NOM corona". The interaction between macromolecules and CdS induced distinct aggregation behaviors in NaCl and CaCl2 solutions. The steric repulsion generated by "NOM corona" significantly stabilized CdS colloids in NaCl solution, and the stabilizing order was consistent with the adsorbing capacity of macromolecules on CdS colloids, namely Bovine serum albumin (BSA) > sodium alginate (SA) > calf thymus DNA (DNA) > Suwannee River humic acid (HA). BSA and DNA also inhibited CdS colloids aggregation in the CaCl2 solution due to the balance of steric hindrance, cation bridging, and electrostatic repulsion. For HA and SA, Ca2+ bridging and EDL compression contributed to their destabilization of CdS colloids in CaCl2 solution. Macromolecules concentration affect corona formation that alter stability of CdS colloids. There results showed that the complex influences of solution chemistry and macromolecules on fate and transport of CdS colloids in environment. The findings will help to understand the potential risks of CdS colloids in environment.
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Affiliation(s)
- Bingcheng Liu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou 510006, PR China
| | - Chuling Guo
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou 510006, PR China.
| | - Changdong Ke
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou 510006, PR China
| | - Kai Chen
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou 510006, PR China
| | - Zhi Dang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou 510006, PR China
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3
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Surette MC, Mitrano DM, Rogers KR. Extraction and concentration of nanoplastic particles from aqueous suspensions using functionalized magnetic nanoparticles and a magnetic flow cell. MICROPLASTICS AND NANOPLASTICS 2023; 3:2. [PMID: 37927349 PMCID: PMC10624164 DOI: 10.1186/s43591-022-00051-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 12/31/2022] [Indexed: 11/07/2023]
Abstract
Although a considerable knowledge base exists for environmental contamination from nanoscale and colloidal particles, significant knowledge gaps exist regarding the sources, transport, distribution, and effects of microplastic pollution (plastic particles < 5 mm) in the environment. Even less is known regarding nanoplastic pollution (generally considered to be plastic particles < 1 μm). Due to their small size, nanoplastics pose unique challenges and potential risks. We herein report a technique focused on the concentration and measurement of nanoplastics in aqueous systems. Hydrophobically functionalized magnetic nanoparticles (HDTMS-FeNPs) were used as part of a method to separate and concentrate nanoplastics from environmentally relevant matrices, here using metal-doped polystyrene nanoplastics (PAN-Pd@NPs) to enable low-level detection and validation of the separation technique. Using a magnetic separation flow cell, PAN-Pd@NPs were removed from suspensions and captured on regenerated cellulose membranes. Depending on the complexity of solution chemistry, variable extraction rates were possible. PAN-Pd@ NPs were recovered from ultrapure water, synthetic freshwater, synthetic freshwater with a model natural organic matter isolate (NOM; Suwannee River Humic Acid), and from synthetic marine water, with recoveries for PAN-Pd@NPs of 84.9%, 78.9%, 70.4%, and 56.1%, respectively. During the initial method testing, it was found that the addition of NaCl was needed in the ultrapure water, synthetic freshwater and synthetic fresh water with NOM to induce particle aggregation and attachment. These results indicate that magnetic nanoparticles in combination with a flow-through system is a promising technique to extract nanoplastics from aqueous suspensions with various compositions.
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Affiliation(s)
- Mark C. Surette
- U.S. EPA Center for Environmental Measurement and Modeling, 109 T.W. Alexander Drive, Research Triangle Park, Durham, NC 27709, USA
- WSP USA Solutions, Inc, 18300 NE Union Hill Road Suite 200, WA 98052 Redmond, USA
| | - Denise M. Mitrano
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Universitatstrasse 16, 8092 Zürich, Switzerland
| | - Kim R. Rogers
- U.S. EPA Center for Environmental Measurement and Modeling, 109 T.W. Alexander Drive, Research Triangle Park, Durham, NC 27709, USA
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Thit A, Grønlund SN, Trudsø LL, Hansen BW, Herzog SD, Nielsen SL, Oturai NG, Posselt D, Ramasamy PK, Sandgaard MH, Syberg K, Selck H, Lyngsie G. Particles as carriers of matter in the aquatic environment: Challenges and ways ahead for transdisciplinary research. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:155831. [PMID: 35568170 DOI: 10.1016/j.scitotenv.2022.155831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/04/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
A diverse array of natural and anthropogenic particles found in the aquatic environment, can act as carriers of co-transported matter (CTM), such as nutrients, genetic material and contaminants. Thus, understanding carrier particle transport will increase our understanding of local and global fluxes of exogenous CTM (affiliated with the particle) and endogenous CTM (an inherent part of the particle). In the present contribution, researchers from multiple disciplines collaborated to provide perspectives on the interactions between carrier particles and CTM, and the fundamentals of transport of particles found in the aquatic environment and the generic spherical smooth particles, often used to make predictions about particle behavior in suspension. Evidently, the particles in the aquatic environment show a great variety of characteristics and vary greatly from each other as well as from the generic particle. However, in spite of these differences, many fundamental concepts apply to particles in general. We emphasize the importance of understanding the basic concepts of transport of particle-associated CTM, and the main assumptions in the generic-founded models, which are challenged by the diverging characteristics of particles found in the aquatic environment, as paramount moving forward. Additionally, we identified the need for a conceptual and semantic link between different scientific fields of particle research and initiated the formation of a consistent terminology. Disciplinary and organizational (academic and funding) barriers need to be overcome to enable individual researchers to move beyond their knowledge sphere, to stimulate future interdisciplinary collaborations and to avoid research silos. Hereby, we can foster faster and better progress of evolving research fields on new and emerging anthropogenic carrier particles, and stimulate the development of solutions to the technological and environmental challenges.
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Affiliation(s)
- Amalie Thit
- Department of Science and Environment, Roskilde University, Denmark.
| | - Sara Nicoline Grønlund
- Department of Science and Environment, Roskilde University, Denmark; Swedish University of Agricultural Sciences, Department of Wildlife, Fish and Environmental Studies, Umeå, Sweden
| | | | | | | | - Søren Laurentius Nielsen
- Department of Science and Environment, Roskilde University, Denmark; Ocean Institute, Læderstræde 20, 1201 København K, Denmark
| | | | - Dorthe Posselt
- Department of Science and Environment, Roskilde University, Denmark
| | | | | | - Kristian Syberg
- Department of Science and Environment, Roskilde University, Denmark
| | - Henriette Selck
- Department of Science and Environment, Roskilde University, Denmark
| | - Gry Lyngsie
- Department of Science and Environment, Roskilde University, Denmark.
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Owoseni O, Su Y, Raghavan S, Bose A, John VT. Hydrophobically modified chitosan biopolymer connects halloysite nanotubes at the oil-water interface as complementary pair for stabilizing oil droplets. J Colloid Interface Sci 2022; 620:135-143. [PMID: 35421750 DOI: 10.1016/j.jcis.2022.03.142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 03/21/2022] [Accepted: 03/30/2022] [Indexed: 10/18/2022]
Abstract
The integration of cationic and hydrophobic functionalities into hydrophobically modified chitosan (HMC) biopolymer facilitates complementary emulsion stabilization with negatively charged halloysite clay nanotubes (HNT). Oil-in-water emulsions with smaller droplet sizes and significantly improved interfacial resistance to droplet coalescence are obtained on complementary emulsion stabilization by HNT and HMC compared to the individual emulsifiers alone. Contact angle measurements shows that the adsorption of the cationic HMC onto the negatively charged HNT modifies the surface wettability of the nanotubes, facilitating the attachment of the nanotubes to the oil-water interface. High resolution cryo-SEM imaging reveals that free HMC chains locks the nanotubes together at the oil-water interface, creating a high barrier to droplet coalescence. The emulsion stability is an order of magnitude higher for conditions in which the aqueous HNT dispersion is stabilized by the HMC compared to conditions where the negatively charged HNT is strongly flocculated by the cationic HMC. The hydrophobic interaction between HMC chains, insertion of HMC hydrophobes into the oil phase and electrostatic interactions between HMC and HNT are proposed as key mechanisms driving the increased emulsion stability. For potential application as a dispersant system for crude oil spill treatment, the nanotubular morphology of HNT was further exploited for the encapsulation of the water-insoluble surfactant, sorbitan monooleate (Span 80). The HMC and HNT sterically strengthens the oil-water interfacial layer while release of the Span 80 surfactant from the HNT lumen lowers the oil-water interfacial tension. The concepts advanced here are relevant in the development of environmentally-benign dispersants for oil spill remediation.
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Affiliation(s)
- Olasehinde Owoseni
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA 70118, United States
| | - Yang Su
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA 70118, United States
| | - Srinivasa Raghavan
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742, United States
| | - Arijit Bose
- Department of Chemical Engineering, University of Rhode Island, Kingston, RI 02881, United States
| | - Vijay T John
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA 70118, United States.
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Mollenkopf M, Fritzsche A, Montalvo D, Diez-Ortiz M, González-Andrés V, Smolders E, Meckenstock R, Totsche KU. Exposure of humic acid-coated goethite colloids to groundwater does not affect their adsorption of metal(loid)s and their impact on Daphnid mobility. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 797:149153. [PMID: 34311365 DOI: 10.1016/j.scitotenv.2021.149153] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
Engineered humic acid-coated goethite (HA-Goe) colloids find increasing application in in situ remediation of metal(loid)-polluted groundwater. Once introduced into the subsurface, the colloids interact with groundwater altering their physicochemical properties. In comparison to freshly synthesized, unreacted HA-Goe colloids, such alterations could reduce the adsorption affinity towards metal(loid)s and also result in altered ecotoxicological effects. In our study, HA-Goe colloids were exposed to two groundwaters (low vs. high concentrations of metal(loid)s) from two metal(loid)-contaminated sites for 87 days. We investigated (i) the course of HA-Goe ecotoxicity (Daphnia magna immobilization tests), (ii) HA-Goe adsorption properties (multi-element solutions containing As, Cu, Zn, Ni and Co), and (iii) changes in the chemical composition as well as in the mineral and aggregate properties of HA-Goe. The adsorption affinity of HA-Goe decreased in the order As ≈ Cu ≫ Zn > Ni ≈ Co. The metal(loid) adsorption occurred rapidly after mixing prior to the first sampling, while the duration of ongoing exposition to groundwater had no effect on the adsorption of these metal(loid)s. We neither observed a desorption of humic acids from the goethite surface nor alterations in the mineralogy, crystallinity, and surface properties of HA-Goe. Standardized Daphnia magna immobilization tests showed an increased number of mobile organisms with increasing exposure time of HA-Goe to both groundwaters. The decrease in HA-Goe-mediated immobilization of D. magna was strongest within the first 30 d. We attribute this to a shift to smaller sizes due to the breakdown of large HA-Goe aggregates, particularly within the first 30 d. The breakdown of these μm-sized aggregates may result mainly from the repeated shaking of the HA-Goe suspensions. Our study confirms within this particular setting that the tested HA-Goe colloids are suitable for the long-term immobilization of metal(loid)s, while lethal effects on D. magna were negligible.
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Affiliation(s)
- Marie Mollenkopf
- Department of Hydrogeology, Institute of Geoscience, Friedrich-Schiller-University Jena, 07749 Jena, Germany
| | - Andreas Fritzsche
- Department of Hydrogeology, Institute of Geoscience, Friedrich-Schiller-University Jena, 07749 Jena, Germany
| | - Daniela Montalvo
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg, Heverlee, Belgium
| | - Maria Diez-Ortiz
- LEITAT Technological Center, c/Pallars 179-185, 08005 Barcelona, Spain
| | | | - Erik Smolders
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg, Heverlee, Belgium
| | | | - Kai Uwe Totsche
- Department of Hydrogeology, Institute of Geoscience, Friedrich-Schiller-University Jena, 07749 Jena, Germany.
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7
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Tou F, Niu Z, Fu J, Wu J, Liu M, Yang Y. Simple Method for the Extraction and Determination of Ti-, Zn-, Ag-, and Au-Containing Nanoparticles in Sediments Using Single-Particle Inductively Coupled Plasma Mass Spectrometry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:10354-10364. [PMID: 34269050 DOI: 10.1021/acs.est.1c00983] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The quantitative analysis of nanoparticles (NPs) in the environment is significantly important for the exploration of the occurrence, fate, and toxicological behaviors of NPs and their subsequent environmental risks. Some protocols have been recommended for the separation and extraction of NPs that are potentially dispersed in complex environmental matrixes, e.g. sediments and soils, but they remain limited. However, certain factors that may significantly affect extraction efficiency have not been comprehensively explored. In this study, on the basis of the single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) technique, a simple standardized protocol for separating and analyzing metal-containing NPs in sediment samples was developed. On consideration of the extraction efficiencies of indigenous NPs (Ti- and Zn-NPs) and spiked NPs (Ag- and Au-NPs) in sediments, sedimentation with a settling time of 6 h is recommended for the separation of NPs and large particles, and the optimal sediment to water ratio, ultrasonication power, time, and temperature are 0.4 mg/mL, 285 W, 20 min, and 15-25 °C, respectively. On the basis of the optimized method, the recoveries of spiked Ag and Au-NPs were 71.4% and 81.1%, respectively. The applicability of the optimal protocols was verified, and TOC was proved to be an important factor controlling the separation and extraction of NPs in environmental samples. The separation and extraction of NPs in elevated TOC samples can be improved by increasing the ultrasonication power, time, and temperature.
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Affiliation(s)
- Feiyun Tou
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, People's Republic of China
| | - Zuoshun Niu
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, People's Republic of China
| | - Jiquan Fu
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, People's Republic of China
| | - Jiayuan Wu
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, People's Republic of China
| | - Min Liu
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, People's Republic of China
- Institute of Eco-Chongming, East China Normal University, Shanghai 200241, People's Republic of China
| | - Yi Yang
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, People's Republic of China
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, People's Republic of China
- Shanghai Key lab for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai 200241, People's Republic of China
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8
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Yang B, Lin H, Bartlett SL, Houghton EM, Robertson DM, Guo L. Partitioning and transformation of organic and inorganic phosphorus among dissolved, colloidal and particulate phases in a hypereutrophic freshwater estuary. WATER RESEARCH 2021; 196:117025. [PMID: 33765499 DOI: 10.1016/j.watres.2021.117025] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Abstract
Phosphorus (P) loadings to the Great Lakes have been regulated for decades, but re-eutrophication and seasonal hypoxia have recently been increasingly reported. It is of paramount importance to better understand the fate, transformation, and biogeochemical cycling processes of different P species across the river-lake interface. We report here results on chemical speciation of P in the seasonally hypoxic Fox River-Green Bay system and variations in sources and partitioning of P species along the aquatic continuum. During midsummer when productivity is generally high, phosphate and dissolved organic P (DOP) were the major species in river water while particulate-organic-P predominated in open bay waters, showing a dynamic change in the chemical speciation of P along the river-bay transect with active transformations between inorganic and organic P and between colloidal and particulate phases. Colloidal organic P (COP, >1 kDa) comprised 33‒65% of the bulk DOP, while colloidal inorganic P was generally insignificant and undetectable especially in open bay water. Sources of COP changed from mainly allochthonous in the Fox River, having mostly smaller sized colloids (1-3 kDa) and a lower organic carbon to phosphorus (C/P) ratio, to predominantly autochthonous in open bay waters with larger sized colloids (>10 kDa) and a higher organic C/P ratio. The observed high apparent distribution coefficients (Kd) of P between dissolved and particulate phases and high-abundant autochthonous colloidal and particulate organic P in the hypereutrophic environment suggest that, in addition to phosphate, colloidal/particulate organic P may play a critical role in the biogeochemical cycling of P and the development of seasonal hypoxia.
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Affiliation(s)
- Bin Yang
- School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 East Greenfield Avenue, Milwaukee, WI 53204, USA; Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf, Beibu Gulf University, Qinzhou 535011, China.
| | - Hui Lin
- School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 East Greenfield Avenue, Milwaukee, WI 53204, USA
| | - Sarah L Bartlett
- New Water, Green Bay Metropolitan Sewerage District, Green Bay, WI 54302, USA
| | - Erin M Houghton
- New Water, Green Bay Metropolitan Sewerage District, Green Bay, WI 54302, USA
| | - Dale M Robertson
- U.S. Geological Survey, Upper Midwest Water Science Center, Middleton, WI 53562, USA
| | - Laodong Guo
- School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 East Greenfield Avenue, Milwaukee, WI 53204, USA.
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9
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Kim C, Pennell KD, Fortner JD. Delineating the Relationship between Nanoparticle Attachment Efficiency and Fluid Flow Velocity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:13992-13999. [PMID: 33052644 DOI: 10.1021/acs.est.0c02669] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The ability to fundamentally describe nanoparticle (NP) transport in the subsurface underpins environmental risk assessment and successful material applications, including advanced remediation and sensing technologies. Despite considerable progress, our understanding of NP deposition behavior remains incomplete as there are conflicting reports regarding the effect of fluid flow velocity on attachment efficiency. To directly address this and more accurately describe NP attachment behavior, we have developed a novel protocol using a quartz crystal microbalance with dissipation monitoring (QCM-D) to separate and individually observe deposition mechanisms (diffusion and sedimentation), providing in situ, real-time information about particle diffusion (from the bulk liquid to solid surface). Through this technique, we have verified that the approaching velocity of NPs via diffusion increases (0.8-6.7 μm/s) with increasing flow velocity (6.1-106.0 μm/s), leading to an increased NP kinetic energy, thus affecting deposition processes. Further, in the presence of a secondary energy minimum associated with organic surface coatings, secondary minimum deposition decreases and primary minimum deposition increases with the flow velocity. NPs deposited at the primary minimum are relatively more resistant to hydrodynamic energies (including detachment associated energies), resulting in an increase of observed attachment efficiencies. Taken together, this work not only describes a novel method to delineate and quantify physical processes underpinning particle behavior but also provides direct measurements regarding key factors defining the relationship(s) of flow velocity and particle attachment. Such insight is valuable for next-generation fate and transport model accuracy, especially under unfavorable attachment regimes, which is a current and critical need for subsurface material applications and implication paradigms.
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Affiliation(s)
- Changwoo Kim
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
| | - Kurt D Pennell
- Civil and Environmental Engineering, Brown University, Providence, Rhode Island 02912, United States
| | - John D Fortner
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
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10
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Qu F, Yang Z, Gao S, Yu H, He J, Rong H, Tian J. Impacts of Natural Organic Matter Adhesion on Irreversible Membrane Fouling during Surface Water Treatment Using Ultrafiltration. MEMBRANES 2020; 10:membranes10090238. [PMID: 32957473 PMCID: PMC7557390 DOI: 10.3390/membranes10090238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 09/11/2020] [Accepted: 09/12/2020] [Indexed: 05/12/2023]
Abstract
To understand impacts of organic adhesion on membrane fouling, ultrafiltration (UF) membrane fouling by dissolved natural organic matter (NOM) was investigated in the presence of background cations (Na+ and Ca2+) at typical concentrations in surface water. Moreover, NOM adhesion on the UF membrane was investigated using atomic force microscopy (AFM) with colloidal probes and a quartz crystal microbalance with dissipation monitoring (QCM-D). The results indicated that the adhesion forces at the NOM-membrane interface increased in the presence of background cations, particularly Ca2+, and that the amount of adhered NOM increased due to reduced electrostatic repulsion. However, the membrane permeability was almost not affected by background cations in the pore blocking-dominated phase but was aggravated to some extent in the cake filtration-governed phase. More importantly, the irreversible NOM fouling was not correlated with the amount of adhered NOM. The assumption for membrane autopsies is doubtful that retained or adsorbed organic materials are necessarily a primary cause of membrane fouling, particularly the irreversible fouling.
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Affiliation(s)
- Fangshu Qu
- School of Civil Engineering, Guangzhou University, Guangzhou 510006, China; (F.Q.); (Z.Y.); (H.Y.); (J.H.); (H.R.)
| | - Zhimeng Yang
- School of Civil Engineering, Guangzhou University, Guangzhou 510006, China; (F.Q.); (Z.Y.); (H.Y.); (J.H.); (H.R.)
| | - Shanshan Gao
- School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, China;
| | - Huarong Yu
- School of Civil Engineering, Guangzhou University, Guangzhou 510006, China; (F.Q.); (Z.Y.); (H.Y.); (J.H.); (H.R.)
| | - Junguo He
- School of Civil Engineering, Guangzhou University, Guangzhou 510006, China; (F.Q.); (Z.Y.); (H.Y.); (J.H.); (H.R.)
| | - Hongwei Rong
- School of Civil Engineering, Guangzhou University, Guangzhou 510006, China; (F.Q.); (Z.Y.); (H.Y.); (J.H.); (H.R.)
| | - Jiayu Tian
- School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, China;
- Correspondence: ; Tel.: +86-1392-8755-563
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11
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Hedberg J, Blomberg E, Odnevall Wallinder I. In the Search for Nanospecific Effects of Dissolution of Metallic Nanoparticles at Freshwater-Like Conditions: A Critical Review. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:4030-4044. [PMID: 30908015 DOI: 10.1021/acs.est.8b05012] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Knowledge on relations between particle properties and dissolution/transformation characteristics of metal and metal oxide nanoparticles (NPs) in freshwater is important for risk assessment and product development. This critical review aims to elucidate nanospecific effects on dissolution of metallic NPs in freshwater and similar media. Dissolution rate constants are compiled and analyzed for NPs of silver (Ag), copper (Cu), copper oxide/hydroxide (CuO, Cu(OH)2), zinc oxide (ZnO), manganese (Mn), and aluminum (Al), showing largely varying (orders of magnitude) constants when modeled using first order kinetics. An effect of small primary sizes (<15 nm) was observed, leading to increased dissolution rate constants and solubility in some cases. However, the often extensive particle agglomeration can result in reduced nanospecific effects on dissolution and also an increased uncertainty related to the surface area, a parameter that largely influence the extent of dissolution. Promising ways to model surface areas of NPs in solution using fractal dimensions and size distributions are discussed in addition to nanospecific aspects related to other processes such as corrosion, adsorption of natural organic matter (NOM), presence of capping agents, and existence of surface defects. The importance of the experimental design on the results of dissolution experiments of metal and metal oxide NPs is moreover highlighted, including the influence of ionic metal solubility and choice of particle dispersion methodology.
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Affiliation(s)
- Jonas Hedberg
- KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Chemistry , Division of Surface and Corrosion Science , Stockholm , Sweden
| | - Eva Blomberg
- KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Chemistry , Division of Surface and Corrosion Science , Stockholm , Sweden
- RISE Research Institutes of Sweden , Division Bioscience and Materials , Stockholm , Sweden
| | - Inger Odnevall Wallinder
- KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Chemistry , Division of Surface and Corrosion Science , Stockholm , Sweden
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12
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Nakano Y, Ochiai A, Kawamoto K, Takeda A, Ichiyoshi K, Ohnuki T, Hochella MF, Utsunomiya S. The competing effects of microbially derived polymeric and low molecular-weight substances on the dispersibility of CeO 2 nanoparticles. Sci Rep 2018; 8:3648. [PMID: 29483563 PMCID: PMC5827655 DOI: 10.1038/s41598-018-21976-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 02/14/2018] [Indexed: 01/15/2023] Open
Abstract
To understand the competing effects of the components in extracellular substances (ES), polymeric substances (PS) and low-molecular-weight small substances (SS) <1 kDa derived from microorganisms, on the colloidal stability of cerium dioxide nanoparticles (CeNPs), we investigated their adsorption to sparingly soluble CeNPs at room temperature at pH 6.0. The ES was extracted from the fungus S. cerevisiae. The polypeptides and phosphates in all components preferentially adsorbed onto the CeNPs. The zeta potentials of ES + CeNPs, PS + CeNPs, and SS + CeNPs overlapped on the plot of PS itself, indicating the surface charge of the polymeric substances controls the zeta potentials. The sizes of the CeNP aggregates, 100-1300 nm, were constrained by the zeta potentials. The steric barrier derived from the polymers, even in SS, enhanced the CeNP dispersibility at pH 1.5-10. Consequently, the PS and SS had similar effects on modifying the CeNP surfaces. The adsorption of ES, which contains PS + SS, can suppress the aggregation of CeNPs over a wider pH range than that for PS only. The present study addresses the non-negligible effects of small-sized molecules derived from microbial activity on the migration of CeNP in aquatic environments, especially where bacterial consortia prevail.
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Affiliation(s)
- Yuriko Nakano
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka-shi, 819-0395, Japan
| | - Asumi Ochiai
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka-shi, 819-0395, Japan
| | - Keisuke Kawamoto
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka-shi, 819-0395, Japan
| | - Ayaka Takeda
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka-shi, 819-0395, Japan
| | - Kenta Ichiyoshi
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka-shi, 819-0395, Japan
| | - Toshihiko Ohnuki
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Tecnology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Michael F Hochella
- Department of Geosciences, Virginia Tech, Blacksburg, VA, 24061, USA.,Subsurface Science and Technology Group, Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Satoshi Utsunomiya
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka-shi, 819-0395, Japan.
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13
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Li Z, Sahle-Demessie E, Aly Hassan A, Pressman JG, Sorial GA, Han C. Effects of source and seasonal variations of natural organic matters on the fate and transport of CeO 2 nanoparticles in the environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 609:1616-1626. [PMID: 28810513 PMCID: PMC6702457 DOI: 10.1016/j.scitotenv.2017.07.154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/17/2017] [Accepted: 07/17/2017] [Indexed: 05/17/2023]
Abstract
Natural organic matter (NOM) affects the stability and transport of nanoparticles (NPs) in natural waters by modifying their physiochemical properties. Source location, and seasonal variations, influence their molecular, physical and electrical charge properties. To understand the variations of NOM on the mobilization of NPs, large volumes of water were collected from the Ohio River (OR) over winter and summer seasons and dissolved NOMs were concentrated. The chemical and structural differences of these NOMs were compared with the Suwannee River humic acid (SRHA) SRHA using 1H and 13C nuclear magnetic resonance spectroscopy, and Fourier transforms infrared (FTIR) spectroscopy. Thermal analysis and FTIR confirmed that differences in composition, structure, and functional groups are a result of SRHA fractionation compared to whole molecule OR-NOM. The influence of OR-NOMs on the surface charge of CeO2 NPs and the effects on the transport and retention in a three-phase (deposition-rinse-re-entrainment) sand-packed columns were investigated at CeO2 NPs initial concertation of 10ppm, pH6.8, increasing ionic strength (3, 5, and 10mM), retention time of 1min, and increasing NOM concentration (1, 5, and 10ppm). The summer OR-NOM showed higher stabilization and mobilization effect on the CeO2 than the winter NOM; while their effect was very different form the SRHA. The stabilization of NPs is attributed to both electrostatic and steric effects. The differences in the chemical structure of the complex and heterogeneous NOMs showed disparate reactivity and direct impact on CeO2-NPs stability. Using SRHA to study the effect of NOM for drinking water related assessment does not sufficiently represent the natural conditions of the environment.
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Affiliation(s)
- Zhen Li
- Environmental Engineering Program, Department of Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, P.O. Box 210012, Cincinnati, OH 45221-0012, United States
| | - Endalkachew Sahle-Demessie
- U.S. Environmental Protection Agency, Office of Research and Development, NRMRL, 26 W. Martin Luther King Drive (MS 443), Cincinnati, OH 45268, United States.
| | - Ashraf Aly Hassan
- Department of Civil Engineering, University of Nebraska Lincoln, P.O. Box 886105, Lincoln, NE 68588-6105, United States
| | - Jonathan G Pressman
- U.S. Environmental Protection Agency, Office of Research and Development, NRMRL, 26 W. Martin Luther King Drive (MS 443), Cincinnati, OH 45268, United States
| | - George A Sorial
- Environmental Engineering Program, Department of Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, P.O. Box 210012, Cincinnati, OH 45221-0012, United States
| | - Changseok Han
- U.S. Environmental Protection Agency, Office of Research and Development, NRMRL, 26 W. Martin Luther King Drive (MS 443), Cincinnati, OH 45268, United States
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14
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Herzog SD, Persson P, Kritzberg ES. Salinity Effects on Iron Speciation in Boreal River Waters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:9747-9755. [PMID: 28836428 DOI: 10.1021/acs.est.7b02309] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Previous studies report high and increasing iron (Fe) concentrations in boreal river mouths. This Fe has shown relatively high stability to salinity-induced aggregation in estuaries. The aim of this study was to understand how the speciation of Fe affects stability over salinity gradients. For Fe to remain in suspension interactions with organic matter (OM) are fundamental and these interactions can be divided in two dominant phases: organically complexed Fe, and colloidal Fe (oxy)hydroxides, stabilized by surface interactions with OM. The stability of these two Fe phases was tested using mixing experiments with river water and artificial seawater. Fe speciation of river waters and salinity-induced aggregates was determined by synchrotron-based extended X-ray absorption fine structure (EXAFS) spectroscopy. The relative contribution of the two Fe phases varied widely across the sampled rivers. Moreover, we found selective removal of Fe (oxy)hydroxides by aggregation at increasing salinity, while organically complexed Fe was less affected. However, Fe-OM complexes were also found in the aggregates, illustrating that the control of Fe stability is not explained by the prevalence of the respective Fe phases alone. Factors such as colloid size and the chemical composition of the OM may also impact the behavior of Fe species.
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Affiliation(s)
- Simon D Herzog
- Department of Biology/Aquatic Ecology, Lund University , SE-223 62, Lund, Sweden
| | - Per Persson
- Centre for Environmental and Climate Research & Department of Biology, Lund University , SE-223 62, Lund, Sweden
| | - Emma S Kritzberg
- Department of Biology/Aquatic Ecology, Lund University , SE-223 62, Lund, Sweden
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15
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Chan AJ, Sarkar P, Gaboriaud F, Fontaine-Aupart MP, Marlière C. Control of interface interactions between natural rubber and solid surfaces through charge effects: an AFM study in force spectroscopic mode. RSC Adv 2017. [DOI: 10.1039/c7ra08589c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Adhesion of nanoparticles (natural rubber) is monitored by slight changes in the surface charge state of the contacting solid surfaces.
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Affiliation(s)
- Alan Jenkin Chan
- Institut des Sciences Moléculaires d'Orsay, ISMO
- Université Paris-Sud
- CNRS
- 91405 Orsay Cedex
- France
| | | | - Fabien Gaboriaud
- Manufacture Française des Pneumatiques Michelin
- F-63040 Clermont Ferrand 9
- France
| | | | - Christian Marlière
- Institut des Sciences Moléculaires d'Orsay, ISMO
- Université Paris-Sud
- CNRS
- 91405 Orsay Cedex
- France
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16
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Lin D, Drew Story S, Walker SL, Huang Q, Cai P. Influence of extracellular polymeric substances on the aggregation kinetics of TiO 2 nanoparticles. WATER RESEARCH 2016; 104:381-388. [PMID: 27576157 DOI: 10.1016/j.watres.2016.08.044] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 08/11/2016] [Accepted: 08/21/2016] [Indexed: 06/06/2023]
Abstract
The early stage of aggregation of titanium oxide (TiO2) nanoparticles was investigated in the presence of extracellular polymeric substance (EPS) constituents and common monovalent and divalent electrolytes through time-resolved dynamic light scattering (DLS). The hydrodynamic diameter was measured and the subsequent aggregation kinetics and attachment efficiencies were calculated across a range of 1-500 mM NaCl and 0.05-40 mM CaCl2 solutions. TiO2 particles were significantly aggregated in the tested range of monovalent and divalent electrolyte concentrations. The aggregation behavior of TiO2 particles in electrolyte solutions was in excellent agreement with the predictions based on Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Divalent electrolytes were more efficient in destabilizing TiO2 particles, as indicated by the considerably lower critical coagulation concentrations (CCC) (1.3 mM CaCl2 vs 11 mM NaCl). The addition of EPS to the NaCl and low concentration CaCl2 (0.05-10 mM) solutions resulted in a dramatic decrease in the aggregation rate and an increase in the CCC values. For solutions of 11 mM NaCl (the CCC values of TiO2 in the absence of EPS) and above, the resulting attachment efficiency was less than one, suggesting that the adsorbed EPS on the TiO2 nanoparticles led to steric repulsion, which effectively stabilized the nanoparticle suspension. At high CaCl2 concentrations (10-40 mM), however, the presence of EPS increased the aggregation rate. This is attributed to the aggregation of the dissolved extracellular polymeric macromolecules via intermolecular bridging, which in turn linked the TiO2 nanoparticles and aggregates together, resulting in enhanced aggregate growth. These results have important implications for assessing the fate and transport of TiO2 nanomaterials released in aquatic environments.
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Affiliation(s)
- Di Lin
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - S Drew Story
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA
| | - Sharon L Walker
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Peng Cai
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
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17
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Tiraferri A, Borkovec M. Probing effects of polymer adsorption in colloidal particle suspensions by light scattering as relevant for the aquatic environment: An overview. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 535:131-140. [PMID: 25434471 DOI: 10.1016/j.scitotenv.2014.11.063] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 11/19/2014] [Accepted: 11/19/2014] [Indexed: 06/04/2023]
Abstract
Modification of particle surfaces by adsorption of polymers is a process that governs particle behavior in aqueous environmental systems. The present article briefly reviews the current understanding of the adsorption mechanisms and the properties of the resulting layers, and it discusses two environmentally relevant cases of particle modification by polymers. In particular, the discussion focuses on the usefulness of methods based on light scattering to probe such adsorbed layers together with the resulting properties of the particle suspensions, and it highlights advantages and disadvantages of these techniques. Measurement of the electrophoretic mobility allows to follow the development of the adsorption layer and to characterize the charge of the modified particles. At saturation, the surface charge is governed by the charge of the adsorbed film. Dynamic light scattering provides information on the film thickness and on the behavior of the modified suspensions. The charge and the structure of the adsorbed layer influence the stability of the particles, as well as the applicability of the classical theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO). This fundamental knowledge is presented in the light of environmental systems and its significance for applied systems is underlined. In particular, the article discusses two examples of environmental processes involving adsorption of polymers, namely, the modification of particles by natural adsorption of humic substances and the tailoring of surface properties of iron-based particles used to remediate contaminated aquifers.
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Affiliation(s)
- Alberto Tiraferri
- Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, Quai Ernest-Ansermet 30, 1205 Geneva, Switzerland.
| | - Michal Borkovec
- Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, Quai Ernest-Ansermet 30, 1205 Geneva, Switzerland
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18
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Efficient bacteria capture and inactivation by cetyltrimethylammonium bromide modified magnetic nanoparticles. Colloids Surf B Biointerfaces 2015; 136:659-65. [PMID: 26496472 DOI: 10.1016/j.colsurfb.2015.10.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 09/11/2015] [Accepted: 10/06/2015] [Indexed: 12/21/2022]
Abstract
Functionalized magnetic nanoparticles have shown great application potentials in water treatment processes especially for bacterial removal. Antibacterial agent, cetyltrimethylammonium bromide (CTAB), was employed to modify Fe3O4 nanoparticles to fabricate bactericidal paramagnetic nanoparticles (Fe3O4@CTAB). The as-prepared Fe3O4@CTAB could effectively capture both Gram-negative Escherichia coli and Gram-positive Bacillus subtilis from water. For both cell types, more than 99% of bacteria with initial concentration of 1.5 × 10(7)CFU/mL could be inactivated by Fe3O4@CTAB (0.5 g/L) within 60 min. Fe3O4@CTAB could remove more than 99% of cells over a wide pH (from 3 to 10) and solution ionic strength range (from 0 to 1000 mM). The copresence of sulfate and nitrate did not affect the bacterial capture efficiencies, whereas, phosphate and silicate slightly decreased the bacterial removal rates. However, more than 91% and 81% of cells could be captured at 10mM of phosphate and silicate, respectively. Over 80% of cells could be removed even in the presence of 10mg/L of humic acid. Moreover, Fe3O4@CTAB exhibited good reusability, and greater than 83% of cells could be captured even in the fifth regeneration cycle. Fe3O4@CTAB prepared in this study have great application potentials for water disinfection.
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19
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Du X, Wang X, You S, Wang Q, Gong X. A case study of aggregation behaviors of titanium dioxide nanoparticles in the presence of dodecylbenzene sulfonate in natural water. J Environ Sci (China) 2015; 36:84-92. [PMID: 26456610 DOI: 10.1016/j.jes.2015.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 05/14/2015] [Accepted: 05/15/2015] [Indexed: 06/05/2023]
Abstract
The present work aims to ascertain the mechanisms of surfactant (dodecylbenzene sulfonate; DBS) effects on the aggregation behaviors of TiO2 nanoparticles (TiO2-NPs) in natural water samples. Aggregation experiments were conducted at a TiO2-NPs concentration of 10mg/L in deionized water and in natural water samples via dynamic light scattering and Zeta potential determination. Average attachment efficiency was calculated to compare the aggregation behaviors of nanoparticles in the two aqueous media. Results showed that the effects of DBS on aggregation could be interpreted by both Derjaguin-Landau-Verwey-Overbeek (DLVO) and non-DLVO mechanisms. In natural water samples, aggregation did not occur rapidly and was able to develop slowly under all conditions, and the roles of DBS were obvious at high DBS concentration owing to the impacts of inherent components of natural water samples, such as colloids and natural organic compounds. Future aggregation studies should concentrate on multi-factor, multi-colloidal and dynamic aspects under similar environmental conditions.
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Affiliation(s)
- Xin Du
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Xiuheng Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Shijie You
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Qiuru Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Xiaobo Gong
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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20
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Keramati H, Saidi MH, Zabetian M. Stabilization of the Suspension of Zirconia Microparticle Using the Nanoparticle Halos Mechanism: Zeta Potential Effect. J DISPER SCI TECHNOL 2015. [DOI: 10.1080/01932691.2015.1015077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Villacorte LO, Ekowati Y, Neu TR, Kleijn JM, Winters H, Amy G, Schippers JC, Kennedy MD. Characterisation of algal organic matter produced by bloom-forming marine and freshwater algae. WATER RESEARCH 2015; 73:216-230. [PMID: 25682049 DOI: 10.1016/j.watres.2015.01.028] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 01/16/2015] [Accepted: 01/20/2015] [Indexed: 06/04/2023]
Abstract
Algal blooms can seriously affect the operation of water treatment processes including low pressure (micro- and ultra-filtration) and high pressure (nanofiltration and reverse osmosis) membranes mainly due to accumulation of algal-derived organic matter (AOM). In this study, the different components of AOM extracted from three common species of bloom-forming algae (Alexandrium tamarense, Chaetoceros affinis and Microcystis sp.) were characterised employing various analytical techniques, such as liquid chromatography - organic carbon detection, fluorescence spectroscopy, fourier transform infrared spectroscopy, alcian blue staining and lectin staining coupled with laser scanning microscopy to indentify its composition and force measurement using atomic force microscopy to measure its stickiness. Batch culture monitoring of the three algal species illustrated varying characteristics in terms of growth pattern, cell concentration and AOM release. The AOM produced by the three algal species comprised mainly biopolymers (e.g., polysaccharides and proteins) but some refractory compounds (e.g., humic-like substances) and other low molecular weight acid and neutral compounds were also found. Biopolymers containing fucose and sulphated functional groups were found in all AOM samples while the presence of other functional groups varied between different species. A large majority (>80%) of the acidic polysaccharide components (in terms of transparent exopolymer particles) were found in the colloidal size range (<0.4 μm). The relative stickiness of AOM substantially varied between algal species and that the cohesion between AOM-coated surfaces was much stronger than the adhesion of AOM on AOM-free surfaces. Overall, the composition as well as the physico-chemical characteristics (e.g., stickiness) of AOM will likely dictate the severity of fouling in membrane systems during algal blooms.
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Affiliation(s)
- L O Villacorte
- UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, Netherlands; Wetsus Center of Excellence for Sustainable Water Technology, Agora 1, 8934 CJ Leeuwarden, Netherlands.
| | - Y Ekowati
- UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, Netherlands
| | - T R Neu
- Department of River Ecology, Helmholtz Centre for Environmental Research (UFZ), Brueckstrasse 3A, 39114 Magdeburg, Germany
| | - J M Kleijn
- Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703HB Wageningen, Netherlands
| | - H Winters
- Water Desalination and Reuse Center, King Abdullah University of Science and Technology, 4700 KAUST, Thuwal, Saudi Arabia; Fairleigh Dickinson University, Teaneck, NJ 07666, USA
| | - G Amy
- UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, Netherlands; Water Desalination and Reuse Center, King Abdullah University of Science and Technology, 4700 KAUST, Thuwal, Saudi Arabia; Delft University of Technology, Stevinweg 1, 2628 CN Delft, Netherlands
| | - J C Schippers
- UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, Netherlands
| | - M D Kennedy
- UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, Netherlands; Delft University of Technology, Stevinweg 1, 2628 CN Delft, Netherlands
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22
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Swindle AL, Cozzarelli IM, Elwood Madden AS. Using chromate to investigate the impact of natural organics on the surface reactivity of nanoparticulate magnetite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2156-62. [PMID: 25607467 DOI: 10.1021/es504831d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Chromate was used as a chemical probe to investigate the size-dependent influence of organics on nanoparticle surface reactivity. Magnetite-chromate sorption experiments were conducted with ∼ 90 and ∼ 6 nm magnetite nanoparticles in the presence and absence of fulvic acid (FA), natural organic matter (NOM), and isolated landfill leachate (LL). Results indicated that low concentrations (1 mg/L) of organics had no noticeable impact on chromate sorption, whereas concentrations of 50 mg/L or more resulted in decreased amounts of chromate sorption. The adsorption of organics onto the magnetite surfaces interfered equally with the ability of the 6 and 90 nm particles to sorb chromate from solution, despite the greater surface area of the smaller particles. Results indicate the presence of organics did not impact the redox chemistry of the magnetite-chromate system over the duration of the experiments (8 h), nor did the organics interact with the chromate in solution. Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM) results indicate that the organics blocked the surface reactivity by occupying surface sites on the particles. The similarity of results with FA and NOM suggests that coverage of the reactive mineral surface is the main factor behind the inhibition of surface reactivity in the presence of organics.
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Affiliation(s)
- Andrew L Swindle
- Department of Geology, Wichita State University , 1845 Fairmount Avenue, Wichita, Kansas 67260, United States
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23
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Heni W, Vonna L, Haidara H. Experimental characterization of the nanoparticle size effect on the mechanical stability of nanoparticle-based coatings. NANO LETTERS 2015; 15:442-9. [PMID: 25495006 DOI: 10.1021/nl503768r] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We present an experimental investigation of the mechanical stability of silica nanoparticle-based coatings as a function of the size of the nanoparticles. The coatings are built following a layer-by-layer procedure, alternating positive and negative surface charges. The mechanical stability of the multilayers is studied in water, on the basis of an ultrasonic cavitation test. The resistance of the coating to cavitation is found to remarkably increase with decreasing the size of the nanoparticles, indicating an increase of the cohesive energy density. The relative contribution of van der Waals and electrical double-layer interactions to the stability of the multilayer is discussed toward their size dependence.
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Affiliation(s)
- Wajdi Heni
- Institut de Science des Matériaux de Mulhouse (IS2M) CNRS-UMR 7361, Université de Haute Alsace , 15 rue Jean Starcky BP2488, 68057 Mulhouse Cedex, France
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24
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Swindle AL, Madden ASE, Cozzarelli IM, Benamara M. Size-dependent reactivity of magnetite nanoparticles: a field-laboratory comparison. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:11413-20. [PMID: 25203482 DOI: 10.1021/es500172p] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Logistic challenges make direct comparisons between laboratory- and field-based investigations into the size-dependent reactivity of nanomaterials difficult. This investigation sought to compare the size-dependent reactivity of nanoparticles in a field setting to a laboratory analog using the specific example of magnetite dissolution. Synthetic magnetite nanoparticles of three size intervals, ∼ 6 nm, ∼ 44 nm, and ∼ 90 nm were emplaced in the subsurface of the USGS research site at the Norman Landfill for up to 30 days using custom-made subsurface nanoparticle holders. Laboratory analog dissolution experiments were conducted using synthetic groundwater. Reaction products were analyzed via TEM and SEM and compared to initial particle characterizations. Field results indicated that an organic coating developed on the particle surfaces largely inhibiting reactivity. Limited dissolution occurred, with the amount of dissolution decreasing as particle size decreased. Conversely, the laboratory analogs without organics revealed greater dissolution of the smaller particles. These results showed that the presence of dissolved organics led to a nearly complete reversal in the size-dependent reactivity trends displayed between the field and laboratory experiments indicating that size-dependent trends observed in laboratory investigations may not be relevant in organic-rich natural systems.
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Affiliation(s)
- Andrew L Swindle
- Department of Geology, Wichita State University , Wichita, Kansas 67260, United States
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Zhao W, Walker SL, Huang Q, Cai P. Adhesion of bacterial pathogens to soil colloidal particles: influences of cell type, natural organic matter, and solution chemistry. WATER RESEARCH 2014; 53:35-46. [PMID: 24495985 DOI: 10.1016/j.watres.2014.01.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 11/20/2013] [Accepted: 01/05/2014] [Indexed: 06/03/2023]
Abstract
Bacterial adhesion to granular soil particles is well studied; however, pathogen interactions with naturally occurring colloidal particles (<2 μm) in soil has not been investigated. This study was developed to identify the interaction mechanisms between model bacterial pathogens and soil colloids as a function of cell type, natural organic matter (NOM), and solution chemistry. Specifically, batch adhesion experiments were conducted using NOM-present, NOM-stripped soil colloids, Streptococcus suis SC05 and Escherichia coli WH09 over a wide range of solution pH (4.0-9.0) and ionic strength (IS, 1-100 mM KCl). Cell characterization techniques, Freundlich isotherm, and Derjaguin-Landau-Verwey-Overbeek (DLVO) theory (sphere-sphere model) were utilized to quantitatively determine the interactions between cells and colloids. The adhesion coefficients (Kf) of S. suis SC05 to NOM-present and NOM-stripped soil colloids were significantly higher than E. coli WH09, respectively. Similarly, Kf values of S. suis SC05 and E. coli WH09 adhesion to NOM-stripped soil colloids were greater than those colloids with NOM-present, respectively, suggesting NOM inhibits bacterial adhesion. Cell adhesion to soil colloids declined with increasing pH and enhanced with rising IS (1-50 mM). Interaction energy calculations indicate these adhesion trends can be explained by DLVO-type forces, with S. suis SC05 and E. coli WH09 being weakly adhered in shallow secondary energy minima via polymer bridging and charge heterogeneity. S. suis SC05 adhesion decreased at higher IS 100 mM, which is attributed to the change of hydrophobic effect and steric repulsion resulted from the greater presence of extracellular polymeric substances (EPS) on S. suis SC05 surface as compared to E. coli WH09. Hence, pathogen adhesion to the colloidal material is determined by a combination of DLVO, charge heterogeneity, hydrophobic and polymer interactions as a function of solution chemistry.
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Affiliation(s)
- Wenqiang Zhao
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Sharon L Walker
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Peng Cai
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
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Hierro A, Olías M, Ketterer ME, Vaca F, Borrego J, Cánovas CR, Bolivar JP. Geochemical behavior of metals and metalloids in an estuary affected by acid mine drainage (AMD). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:2611-2627. [PMID: 24096526 DOI: 10.1007/s11356-013-2189-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 09/23/2013] [Indexed: 06/02/2023]
Abstract
The Tinto and Odiel rivers in southwest Spain drain the world's largest sulfide mineral formation: the Iberian Pyrite Belt which has been worked since 2,500 BC. The Tinto and Odiel estuarine zones include both an extensive area of salt marsh and an intensively industrialized urban area. As a consequence of pyrite oxidation, the Tinto and Odiel rivers are strongly acidic (pH < 3) with unusually high and quite variable metal concentrations. In this study, seasonally varying concentrations of dissolved major and trace elements were determined in the acid mine drainage affected estuary of the Ría de Huelva. During estuarine mixing, ore-derived metal concentrations exhibit excellent correlations with pH as the main controlling parameter. As pH increases, concentrations of dissolved ore-associated elements are attenuated, and this process is enhanced during the summer months. The decrease in Fe and Al concentrations ranged from 80 to 100 % as these elements are converted from dissolved to sediment-associated forms in the estuary. Coprecipitation/adsorption processes also removed between 60 and 90 % of the originally dissolved Co, Cu, Mn, Pb, Zn, and Th; however, Cd and Ni exhibited a greater propensity to remain in solution, with an average removal of approximately 60 %. On the other hand, As and U exhibited a different behavior; it is likely that these elements remain in dissolved forms because of the formation of U carbonates and soluble As species. Concentrations of As remain at elevated levels in the outer estuary (average = 48 μg L(-1)) which exceeds concentrations present in the Tinto River. Nevertheless, the estuary has recently witnessed improvements in water quality, as compared to results of several previous studies reported in the 1990s.
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Affiliation(s)
- A Hierro
- Department of Applied Physics, Facultad de Ciencias Experimentales, University of Huelva, Campus de El Carmen, 21071, Huelva, Spain
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27
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Mosley LM, Zammit B, Jolley AM, Barnett L, Fitzpatrick R. Monitoring and assessment of surface water acidification following rewetting of oxidised acid sulfate soils. ENVIRONMENTAL MONITORING AND ASSESSMENT 2014; 186:1-18. [PMID: 23900634 DOI: 10.1007/s10661-013-3350-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 07/10/2013] [Indexed: 06/02/2023]
Abstract
Large-scale exposure of acid sulfate soils during a hydrological drought in the Lower Lakes of South Australia resulted in acidification of surface water in several locations. Our aim was to describe the techniques used to monitor, assess and manage these acidification events using a field and laboratory dataset (n = 1,208) of acidic to circum-neutral pH water samples. The median pH of the acidified (pH < 6.5) samples was 3.8. Significant (p < 0.05) increases in soluble metals (Al, Co, Mn, Ni and Zn above guidelines for ecosystem protection), SO4 (from pyrite oxidation), Si (from aluminosilicate dissolution) and Ca (from carbonate dissolution and limestone addition), were observed under the acidic conditions. The log of the soluble metal concentrations, acidity and SO4/Cl ratio increased linearly with pH. The pH, alkalinity and acidity measurements were used to inform aerial limestone dosing events to neutralise acidic water. Field measurements correlated strongly with laboratory measurements for pH, alkalinity and conductivity (r (2) ≥ 0.97) but only moderately with acidity (r (2) = 0.54), which could be due to difficulties in determining the indicator-based field titration endpoint. Laboratory measured acidity correlated well with calculated acidity (r (2) = 0.87, acidity present as Al(III) >> H(+) ≈ Mn(II) > Fe(II/III)) but was about 20 % higher on average. Geochemical speciation calculations and XRD measurements indicated that solid phase minerals (schwertmannite and jarosite for Fe and jurbanite for Al) were likely controlling dissolved metal concentrations and influencing measured acidity between pH 2 and 5.
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Affiliation(s)
- Luke M Mosley
- Water Quality Branch, Environment Protection Authority (South Australia), GPO Box 2607, Adelaide, SA, 5001, Australia,
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28
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Romanello MB, Fidalgo de Cortalezzi MM. An experimental study on the aggregation of TiO2 nanoparticles under environmentally relevant conditions. WATER RESEARCH 2013; 47:3887-3898. [PMID: 23579091 DOI: 10.1016/j.watres.2012.11.061] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 09/28/2012] [Accepted: 11/18/2012] [Indexed: 06/02/2023]
Abstract
The eventual future scenario of a release of nanomaterials into the environment makes it necessary to assess the risk involved in their use by studying their behavior in natural waters. NanoTiO2 is one of the most commonly employed nanomaterials. In the present work we studied the aggregation rates, aggregate size and aggregate morphology of NanoTiO2 under the presence of inert electrolytes, divalent cations, and these two combined with natural organic matter, in an effort to provide a comprehensive investigation of the phenomena of interaction of nanomaterials and natural waters and elucidate some of the conflicting information reported in the literature. The stability of nanoparticles could be explained in all cases, at least qualitatively, in terms of classical DLVO interactions (Electrical Double Layer, Van der Waals). Divalent cations were adsorbed to the surface of the nanoparticles, neutralizing the negative charge at pH values greater than the point of zero charge and inducing aggregation. Natural organic matter (NOM) adsorbed to the particles and made their zeta potential more negative, hence stabilizing them by lowering the pH of maximum aggregation. Divalent cations partially neutralized the adsorbed NOM, and at high concentrations aggregation was observed with Ca(2+) but not Mg(2+), suggesting the presence of specific Ca(2+)-NOM bridges. SEM images visually revealed a fractal-like morphology of the aggregates formed under unfavorable conditions.
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Affiliation(s)
- Marina Belen Romanello
- Department of Chemical Engineering, Instituto Tecnológico de Buenos Aires, Av. Madero 399, Buenos Aires, Argentina; CONICET, Argentina.
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Aubry C, Gutierrez L, Croue JP. Coating of AFM probes with aquatic humic and non-humic NOM to study their adhesion properties. WATER RESEARCH 2013; 47:3109-3119. [PMID: 23587263 DOI: 10.1016/j.watres.2013.03.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 03/02/2013] [Accepted: 03/09/2013] [Indexed: 06/02/2023]
Abstract
Atomic force microscopy (AFM) was used to study interaction forces between four Natural Organic Matter (NOM) samples of different physicochemical characteristics and origins and mica surface at a wide range of ionic strength. All NOM samples were strongly adsorbed on positively charged iron oxide-coated silica colloidal probe. Cross-sectioning by focused ion beam milling technique and elemental mapping by energy-filtered transmission electron microscopy indicated coating completeness of the NOM-coated colloidal probes. AFM-generated force-distance curves were analyzed to elucidate the nature and mechanisms of these interacting forces. Electrostatics and steric interactions were important contributors to repulsive forces during approach, although the latter became more influential with increasing ionic strength. Retracting force profiles showed a NOM adhesion behavior on mica consistent with its physicochemical characteristics. Humic-like substances, referred as the least hydrophilic NOM fraction, i.e., so called hydrophobic NOM, poorly adsorbed on hydrophilic mica due to their high content of ionized carboxyl groups and aromatic/hydrophobic character. However, adhesion force increased with increasing ionic strength, suggesting double layer compression. Conversely, polysaccharide-like substances showed high adhesion to mica. Hydrogen-bonding between hydroxyl groups on polysaccharide-like substances and highly electronegative elements on mica was suggested as the main adsorption mechanism, where the adhesion force decreased with increasing ionic strength. Results from this investigation indicated that all NOM samples retained their characteristics after the coating procedure. The experimental approach followed in this study can potentially be extended to investigate interactions between NOM and clean or fouled membranes as a function of NOM physicochemical characteristics and solution chemistry.
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Affiliation(s)
- Cyril Aubry
- Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
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30
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Ferris RJ, Lin S, Therezien M, Yellen BB, Zauscher S. Electric double layer formed by polarized ferroelectric thin films. ACS APPLIED MATERIALS & INTERFACES 2013; 5:2610-2617. [PMID: 23484485 DOI: 10.1021/am3031954] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Ferroelectric surfaces can have very high surface charge densities that can be harnessed for manipulation of charged colloidal particles and soft matter in aqueous environments. Here, we report on the electrical double layer (EDL) formed by polarized ultrasmooth lead zirconium titanate (US-PZT) thin films in dilute electrolyte solutions. Using colloidal probe force microscopy (CPFM) measurements, we show that the ion distribution within the double layer can be changed by reversing the ferroelectric polarization state of US-PZT. The interaction force in dilute 1:1 electrolyte solution between the negatively charged probe and a positive surface charge (upward polarized) US-PZT thin film is attractive, while the interaction force is repulsive for a negative surface charge (downward polarized) film. We modeled these interactions with a constant-potential EDL model between dissimilar surfaces with the inclusion of a Stern layer. We report the surface potentials at the inner and outer-Helmholtz planes both for polarization states and for a range of ionic strength solutions. Effects of free-charge carriers, limitations of the analytical model, and effects of surface roughness are discussed.
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Affiliation(s)
- Robert J Ferris
- Department of Mechanical Engineering and Material Science, Duke University, 144 Hudson Hall, Durham, North Carolina 27708, United States
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31
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Borgnino L. Experimental determination of the colloidal stability of Fe(III)-montmorillonite: Effects of organic matter, ionic strength and pH conditions. Colloids Surf A Physicochem Eng Asp 2013. [DOI: 10.1016/j.colsurfa.2013.01.065] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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32
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Schwyzer I, Kaegi R, Sigg L, Smajda R, Magrez A, Nowack B. Long-term colloidal stability of 10 carbon nanotube types in the absence/presence of humic acid and calcium. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2012; 169:64-73. [PMID: 22683482 DOI: 10.1016/j.envpol.2012.05.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 05/03/2012] [Accepted: 05/06/2012] [Indexed: 06/01/2023]
Abstract
The colloidal stabilities of ten carbon nanotubes (CNTs) having varying physico-chemical properties were compared in long-term experiments. The presence of Suwannee River Humic Acid (SRHA) increased the fraction of CNTs in the supernatants (4-88% for the various CNT types) after addition in pre-dispersed form and 20 days of shaking and 5 days of settling. These suspensions were monomodal, containing individually suspended CNTs with highly negative surface charges. Calcium (2 mM) removed most of the CNT types from the supernatant, due to CNT-agglomerate formation initiated by reduction in surface charge. The amount of SRHA adsorbed to the different CNT types did not correlate (r(2) < 0.1) with the percentage of CNTs remaining in suspension. Multiple linear regression analysis revealed that the oxygen content and the diameter of the CNTs significantly influenced the percentage of stabilized CNTs, resulting in an increased fraction of functionalized and large-diameter CNTs that remained in suspension.
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Affiliation(s)
- Irène Schwyzer
- Empa-Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
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33
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Jin Y, Liu F, Tong M, Hou Y. Removal of arsenate by cetyltrimethylammonium bromide modified magnetic nanoparticles. JOURNAL OF HAZARDOUS MATERIALS 2012; 227-228:461-468. [PMID: 22703733 DOI: 10.1016/j.jhazmat.2012.05.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 04/30/2012] [Accepted: 05/02/2012] [Indexed: 06/01/2023]
Abstract
Cetyltrimethylammonium bromide (CTAB) modified magnetic nanoparticles (Fe(3)O(4)@CTAB) were synthesized and used to remove arsenate from water. Fe(3)O(4)@CTAB was prepared by a modified simple co-precipitation process with cheap and environmental friendly iron salts and cationic surfactant CTAB. Powder X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infra-red spectroscopy were utilized to characterize the prepared adsorbent (Fe(3)O(4)@CTAB). Transmission electron microscopy (TEM) image showed that Fe(3)O(4)@CTAB particles were approximately spherical with the core size of 10 nm. With a saturation magnetization of 67.2 emu g(-1), the Fe(3)O(4)@CTAB nanoparticles could be easily separated from solutions with a simple magnetic process in very short time (within 5 min). Adsorption of arsenate on Fe(3)O(4)@CTAB reached equilibrium within 2 min at pH 6. Arsenate adsorption agreed well with pseudo-second order kinetic model and two-site Langmuir isotherm model with the arsenate adsorption capacity of 23.07 mg g(-l), which was twice greater than that of pure Fe(3)O(4). Arsenate removal rate was over 90% at a wide pH range from 3 to 9 and the removal of arsenate was not obviously affected by the presence of dissolved natural organic matter (up to 10 mg L(-1) as TOC) and competitive anions (sulfate, bicarbonate, and silicate up to 20 mg L(-1), and phosphate up to 5 mg L(-1)) in solutions. Fe(3)O(4)@CTAB could be regenerated in alkali solutions and more than 85% As(V) was removed even in fifth regeneration/reuse cycle.
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Affiliation(s)
- Yinjia Jin
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, PR China
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34
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Structure of Colloidal Flocs in relation to the Dynamic Properties of Unstable Suspension. INT J POLYM SCI 2012. [DOI: 10.1155/2012/574878] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dynamic behaviors of unstable colloidal dispersions are reviewed in terms of floc formation. Geometrical structure of flocs in terms of chemical conditions and formation mechanics is a key to predict macroscopic transportation properties. The rate of sedimentation and rheological properties can be described with the help of fractal dimension (D) that is the function of the number of contacts between clusters (Nc). It is also well known that the application of water soluble polymers and polyelectrolytes, which are usually used as a conditioner or flocculants in colloidal dispersions, critically affects the process of flocculation. The resulted floc structure is also influenced by the application of polymer. In order to reveal the roles of the polymers, the elementary rate process of polymer reaching to colloidal interface and subsequent reconformation process into more stable adsorption state are needed to be analyzed. The properties of permeable flocs and adsorbed polymer (polyelectrolyte) layers formed on the colloidal surfaces remain to be worked out in relation to inhomogeneous porous structure and electrokinetics in the future.
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35
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Tong M, Zhu P, Jiang X, Kim H. Influence of natural organic matter on the deposition kinetics of extracellular polymeric substances (EPS) on silica. Colloids Surf B Biointerfaces 2011; 87:151-8. [DOI: 10.1016/j.colsurfb.2011.05.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 04/08/2011] [Accepted: 05/07/2011] [Indexed: 10/18/2022]
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36
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Mitic S, Pustylnik MY, Morfill GE, Kovačević E. In situ characterization of nanoparticles during growth by means of white light scattering. OPTICS LETTERS 2011; 36:3699-3701. [PMID: 21931437 DOI: 10.1364/ol.36.003699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A simple method of characterization of suspensions of spherical nanoparticles with monotonically variable size is proposed. It allows for the in situ measurement of the particle size as well as spectral dependence of their refractive indices. The method requires three optical channels: one for the illumination of a suspension by white light and two for the measurements of the spectra of scattered light. Parameters of the particles are determined by fitting the measured temporal spectral surfaces by the calculated Mie scattering functions. The method is applied to the particles being grown in a low-pressure reactive plasma of a discharge in an acetylene-argon mixture.
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Affiliation(s)
- S Mitic
- Max-Planck-Institut für Extraterrestrische Physik, Garching, Germany.
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37
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Aiken GR, Hsu-Kim H, Ryan JN. Influence of dissolved organic matter on the environmental fate of metals, nanoparticles, and colloids. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:3196-201. [PMID: 21405118 DOI: 10.1021/es103992s] [Citation(s) in RCA: 427] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- George R Aiken
- U.S. Geological Survey , 3215 Marine Street, Boulder, Colorado 80303, United States.
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38
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Quik JTK, Lynch I, Van Hoecke K, Miermans CJH, De Schamphelaere KAC, Janssen CR, Dawson KA, Stuart MAC, Van De Meent D. Effect of natural organic matter on cerium dioxide nanoparticles settling in model fresh water. CHEMOSPHERE 2010; 81:711-715. [PMID: 20728203 DOI: 10.1016/j.chemosphere.2010.07.062] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 07/19/2010] [Accepted: 07/28/2010] [Indexed: 05/29/2023]
Abstract
The ecological risk assessment of chemicals including nanoparticles is based on the determination of adverse effects on organisms and on the environmental concentrations to which biota are exposed. The aim of this work was to better understand the behavior of nanoparticles in the environment, with the ultimate goal of predicting future exposure concentrations in water. We measured the concentrations and particle size distributions of CeO(2) nanoparticles in algae growth medium and deionized water in the presence of various concentrations and two types of natural organic matter (NOM). The presence of natural organic matter stabilizes the CeO(2) nanoparticles in suspension. In presence of NOM, up to 88% of the initially added CeO(2) nanoparticles remained suspended in deionized water and 41% in algae growth medium after 12d of settling. The adsorbed organic matter decreases the zeta potential from about -15 mV to -55 mV. This reduces aggregation by increased electrostatic repulsion. The particle diameter, pH, electric conductivity and NOM content shows significant correlation with the fraction of CeO(2) nanoparticles remaining in suspension.
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Affiliation(s)
- Joris T K Quik
- Department of Environmental Science, Radboud University Nijmegen, Institute for Wetland and Water Research, PO Box 9010, 6500 GL Nijmegen, The Netherlands.
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39
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Liu X, Wazne M, Han Y, Christodoulatos C, Jasinkiewicz KL. Effects of natural organic matter on aggregation kinetics of boron nanoparticles in monovalent and divalent electrolytes. J Colloid Interface Sci 2010; 348:101-7. [DOI: 10.1016/j.jcis.2010.04.036] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 04/15/2010] [Accepted: 04/15/2010] [Indexed: 10/19/2022]
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40
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Kalmykova Y, Rauch S, Strömvall AM, Morrison G, Stolpe B, Hasselliöv M. Colloid-facilitated metal transport in peat filters. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2010; 82:506-511. [PMID: 20572457 DOI: 10.2175/106143009x12529484815430] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The effect of colloids on metal retention in peat columns was studied, with the focus on colloids from two sources-organic matter leached from peat, and introduced organic and hydrous ferric oxide (HFO) colloids. A significant fraction of metals was found to be associated with peat-produced organic colloids; however the concentrations of organic colloids leached are low (trace concentrations) and temporal and have a limited effect on the efficiency of peat filters. In contrast, the presence of organic and HFO colloids in the input water causes a significant decrease in the performance of peat filters. Organic colloids were identified as the main vector of cadmium, copper, nickel, and zinc, while lead is transported by both organic and HFO colloids. The colloidal distribution of metals obtained in this study has important implications for the mobility of trace metals in porous media. The occurrence of colloids in the input waters and their characteristics must be considered when designing water treatment facilities.
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Affiliation(s)
- Yuliya Kalmykova
- Water Environment Technology, Department of Civil and Environmental Engineering, Chalmers University of Technology, Gothenburg, Sweden.
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41
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Ren H, Liu H, Qu J, Berg M, Qi W, Xu W. The influence of colloids on the geochemical behavior of metals in polluted water using as an example Yongdingxin River, Tianjin, China. CHEMOSPHERE 2010; 78:360-367. [PMID: 20006372 DOI: 10.1016/j.chemosphere.2009.11.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 11/10/2009] [Accepted: 11/12/2009] [Indexed: 05/28/2023]
Abstract
The role of colloids in estuarine and marine systems has been studied extensively in recent years, whereas less is known about the polluted freshwater system. Yongdingxin River is one of the major recipients of industrial effluents in Tianjin. This article evaluates the role of colloids in controlling geochemical behavior of Cu, Zn, Fe, Mn, Hg and Cr at the confluences between Yongdingxin River and its major tributaries Beijing Drainage River, Jinzhong River and Beitang Drainage River. Based on the distribution of metal partitioning among particulate (>0.22mum), colloidal (1kDa to 0.22mum) and truly dissolved (<1kDa) fractions, the metals can be assigned to the following groups: Group 1 - organic colloidal pool-borne elements Cu and Cr; Group 2 - inorganic colloidal pool-borne metals Fe and Mn; Group 3 - Zn and Hg characterized by varying complexation patterns. The distribution of metal partitioning among particulate, colloidal and truly dissolved fractions was influenced by anthropogenic input. In addition, the theoretical concentrations of elements in case of conservative mixing between the waters of Yongdingxin River and the waters of its tributaries were compared with the measured values to evaluate the geochemical role of colloids. The result showed that all of the metals presented a non-conservative mixing behavior. Addition of colloids resulted in the removal of metals from the water column to bed sediment during river water mixing, which was furthermore confirmed by the similar partition coefficient of metal concentration between colloid and sediment.
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Affiliation(s)
- Huimin Ren
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China
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42
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Manciulea A, Baker A, Lead JR. A fluorescence quenching study of the interaction of Suwannee River fulvic acid with iron oxide nanoparticles. CHEMOSPHERE 2009; 76:1023-7. [PMID: 19477482 DOI: 10.1016/j.chemosphere.2009.04.067] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Revised: 04/28/2009] [Accepted: 04/29/2009] [Indexed: 05/20/2023]
Abstract
The fluorescence quenching behaviour of a manufactured nanoparticle (NP, iron oxide, 7nm) on the standard Suwannee River fulvic acid (SRFA) was investigated for the first time. Size, aggregation and fluorescence was examined as a function of NP:SRFA ratio and of pH. Aggregation state varied as both a function of pH and NP:SRFA ratio, with maximum aggregation at near neutral pH values (6-8). SRFA fluorescence quenching increased non-linearly with increasing NP concentrations (>0.22x10(-3)M iron nanoparticles), indicating the complex nature of NP:SRFA interactions. Aggregates of iron oxide present at pH7-8 appeared to have a much larger effect on quenching compared with dispersed NPs or dissolved phase iron. Fluorescence quenching is demonstrated to indicate different mechanisms of NP:SRFA binding with pH.
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Li Q, Xie B, Hwang YS, Xu Y. Kinetics of C60 fullerene dispersion in water enhanced by natural organic matter and sunlight. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:3574-3579. [PMID: 19544857 DOI: 10.1021/es803603x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The industrial-scale production of Buckminster fullerene C60 elicits concerns over its impact on human health and ecosystems because of the reported, albeit debatable, toxicity. Assessment of the overall environment risk requires a good estimate of the level of exposure and careful characterization of the physicochemical properties of C60 in natural aqueous environments. The reported study investigates the role of various environmental factors, i.e., ionic composition, natural organic matter (NOM), and light in dispersion of C60 in the aqueous phase by simple mixing. The presence of NOM greatly enhances C60 dispersion, and the dispersion process is further accelerated by sunlight. At typical NOM concentrations found in natural waters, C60 concentrations of a few to tens of milligrams per liter can occur within 10 days of mixing, regardless of its extremely low water solubility. The rate of dispersing decreases with the increase of ionic strength. However, calcium ions significantly increase C60 concentration in the aqueous phase. Results from UV/vis absorbance characterization strongly suggest that C60 may have been chemically modified when dispersed in an NOM solution in the presence of sunlight. This reaction pathway has significant implication on the fate, transport, and environmental impact of C60 fullerene.
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Affiliation(s)
- Qilin Li
- Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005, USA.
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Xie B, Xu Z, Guo W, Li Q. Impact of natural organic matter on the physicochemical properties of aqueous C60 nanoparticles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:2853-2859. [PMID: 18497134 DOI: 10.1021/es702231g] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Existing toxicity data indicate that industrial-scale production of C60 fullerene poses a potential threat to the environment. Evaluating the environmental impact of C60 requires careful characterization of its physicochemical properties in the natural aqueous environment. Our study aims to determine the effects of aquatic natural organic matter (NOM) on the physicochemical properties of aqueous C60 nanoparticles, nC60. Stable nC60 suspensions were formed using three different solvent exchange protocols. They were thoroughly characterized for particle size, morphology, and electrophoretic mobility in the absence or presence of two model NOM components, Suwannee River humic acid and fulvic acid. NOM caused disaggregation of nC60 crystals and aggregates under typical solution conditions of natural water, leading to significant changes in particle size and morphology. Such effect increased with increasing NOM concentration. The changes in nC060 size and morphology strongly depended on the nC60 formation pathway. Results from this study indicate that NOM may play a critical role in the transport and toxicity of C60 in the natural aqueous environment.
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Affiliation(s)
- Bin Xie
- Department of Civil and Environmental Engineering, Rice University, Houston Texas 77005, USA
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45
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Abu-Lail LI, Liu Y, Atabek A, Camesano TA. Quantifying the adhesion and interaction forces between Pseudomonas aeruginosa and natural organic matter. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:8031-8037. [PMID: 18186333 DOI: 10.1021/es071047o] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Atomic force microscopy (AFM) was used to characterize interactions between natural organic matter (NOM), and glass or bacteria. Poly(methacrylic acid) (PMA), soil humic Acid (SHA), and Suwannee River humic Acid (SRHA), were adsorbed to silica AFM probes. Adhesion forces (Fadh) for the interaction of organic-probes and glass slides correlated with organic molecular weight (MW), but not with radius of the organic aggregate (R), charge density (Q), or zeta potential (zeta). Two Pseudomonas aeruginosa strains with different lipopolysaccharides (LPS) were chosen: PAO1 (A+B+), whose LPS have common antigen (A-band) + O-antigen (B-band); and mutant AK1401 (A+B-). Fadh between bacteria and organics correlated with organic MW, R, and Q, but not zeta. PAO1 had lower Fadh with silica than NOM, which was attributed to negative charges from the B-band polymers causing electrostatic repulsion. AK1401 adhered stronger to silica than to the organics, perhaps because the absence of the B-band exposed underlying positively charged proteins. DLVO calculations could not explain the differences in the two bacteria or predict qualitative or quantitative trends in interaction forces in these systems. Molecular-level information from AFM studies can bring us closer to understanding the complex nature of bacterial-NOM interactions.
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Affiliation(s)
- Laila I Abu-Lail
- Department of Civil and Environmental Engineering, Life Sciences and Bioengineering Institute at Gateway Park, Worcester Polytechnic Institute, Worcester, MA 01609, USA
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Baalousha M, Lead JR. Size fractionation and characterization of natural aquatic colloids and nanoparticles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2007; 386:93-102. [PMID: 17644161 DOI: 10.1016/j.scitotenv.2007.05.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Revised: 05/23/2007] [Accepted: 05/25/2007] [Indexed: 05/16/2023]
Abstract
Atomic force microscopy (AFM) was used to image and quantify natural nanoparticles (prefiltered <25 nm) from three different freshwater sites (Vale Lake, Bailey Brook and Tern Rivers). Four fractions were analysed by AFM; the prefiltered fraction (<25 nm) and three fractions collected after separation of this prefiltered sample by flow field-flow fractionation (FlFFF) which corresponds to material which has size ranges of <4.2 nm, 4.2-15.8 nm and 15.8-32.4 nm, as determined by FlFFF theory. The large majority of materials in all samples appeared as <3 nm nanoparticles, nearly spherical and rich in chromophores active at 254 nm UV, which thus correspond to natural organic matter. However, nanoparticles were also imaged up to slightly more than 25 nm in size, indicating a slight disagreement in sizing between filtration and FlFFF. In addition, some particles in certain fractions were found to be covered with a thin film of less than 0.5-1.0 nm. Substantial differences between sites were observed.
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Affiliation(s)
- M Baalousha
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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Liang Y, Hilal N, Langston P, Starov V. Interaction forces between colloidal particles in liquid: theory and experiment. Adv Colloid Interface Sci 2007; 134-135:151-66. [PMID: 17499205 DOI: 10.1016/j.cis.2007.04.003] [Citation(s) in RCA: 221] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 04/02/2007] [Accepted: 04/08/2007] [Indexed: 11/22/2022]
Abstract
The interaction forces acting between colloidal particles in suspensions play an important part in determining the properties of a variety of materials, the behaviour of a range of industrial and environmental processes. Below we briefly review the theories of the colloidal forces between particles and surfaces including London-van der Waals forces, electrical double layer forces, solvation forces, hydrophobic forces and steric forces. In the framework of Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, theoretical predictions of total interparticle interaction forces are discussed. A survey of direct measurements of the interaction forces between colloidal particles as a function of the surface separation is presented. Most of the measurements have been carried out mainly using the atomic force microscopy (AFM) as well as the surface force apparatus (SFA) in the liquid phase. With the highly sophisticated and versatile techniques that are employed by far, the existing interaction theories between surfaces have been validated and advanced. In addition, the direct force measurements by AFM have also been useful in the explaining or understanding of more complex phenomena and in engineering the products and processes occurring in many industrial applications.
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Affiliation(s)
- Yuncheng Liang
- School of Chemical, Environmental and Mining Engineering, The University of Nottingham, University Park, Nottingham, NG7 2RD, UK
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Seredyńska-Sobecka B, Baker A, Lead JR. Characterisation of colloidal and particulate organic carbon in freshwaters by thermal fluorescence quenching. WATER RESEARCH 2007; 41:3069-76. [PMID: 17560624 DOI: 10.1016/j.watres.2007.04.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Revised: 04/13/2007] [Accepted: 04/24/2007] [Indexed: 05/15/2023]
Abstract
Three-dimensional excitation-emission matrix (EEM) fluorescence with thermal quenching has been applied to raw and size-fractionated freshwaters. To size-fractionate organic matter, sequential filtration through mixed-ester-cellulose membrane filters with nominal pore size of 1.2, 0.1 and 0.025 microm were used. Humic-like fluorophores (peaks A and C) have been found to dominate EEMs of raw and all size fractions of studied waters. Peak A fluorescence intensity has been found to be more thermally sensitive than peak C fluorescence intensity. Humic-like fluorescence intensity was generally size independent, which indicated that it was present mainly in the smallest size fraction (<0.025 microm). This was confirmed by total organic carbon (TOC) measurements. Peak T (tryptophan-like) fluorescence, that is widely associated with biological activity, exhibited a greater thermal sensitivity of fluorescence intensity in the larger size fractions, demonstrating the presence of more than one fluorophore in different size fractions at this location in optical space. Thermal fluorescence quenching provides insights into organic matter variability and associated colloidal characteristics.
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Affiliation(s)
- Bozena Seredyńska-Sobecka
- School of Geography, Earth and Environmental Science, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Chen KL, Mylon SE, Elimelech M. Enhanced aggregation of alginate-coated iron oxide (hematite) nanoparticles in the presence of calcium, strontium, and barium cations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:5920-8. [PMID: 17469860 DOI: 10.1021/la063744k] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Early-stage aggregation kinetics studies of alginate-coated hematite nanoparticles in solutions containing alkaline-earth metal cations revealed enhanced aggregation rates in the presence of Ca2+, Sr2+, and Ba2+, but not with Mg2+. Transmission electron microscopy (TEM) imaging of the aggregates provided evidence that alginate gel formation was essential for enhanced aggregation to occur. Dynamic light scattering (DLS) aggregation results clearly indicated that a much lower concentration of Ba2+ compared to Ca2+ and Sr2+ was required to achieve a similar degree of enhanced aggregation in each system. To elucidate the relationship between the alginate's affinities for divalent cations and the enhanced aggregation of the alginate-coated hematite nanoparticles, atomic force microscopy (AFM) was employed to probe the interaction forces between alginate-coated hematite surfaces under the solution chemistries used for the aggregation study. Maximum adhesion forces, maximum pull-off distances, and the work of adhesion were used as indicators to gauge the alginate's affinity for the divalent cations and the resulting attractive interactions between alginate-coated hematite nanoparticles. The results showed that alginate had higher affinity for Ba2+ than either Sr2+ or Ca2+. This same trend was consistent with the cation concentrations required for comparable enhanced aggregation kinetics, suggesting that the rate of alginate gel formation controls the enhanced aggregation kinetics. An aggregation mechanism incorporating the gelation of alginate is proposed to explain the accelerated aggregate growth in the presence of Ca2+, Sr2+, and Ba2+.
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Affiliation(s)
- Kai Loon Chen
- Department of Chemical Engineering, Environmental Engineering Program, Yale University, New Haven, Connecticut 06520-8286, USA
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50
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Harbour PJ, Dixon DR, Scales PJ. The role of natural organic matter in suspension stability. Colloids Surf A Physicochem Eng Asp 2007. [DOI: 10.1016/j.colsurfa.2006.08.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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