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Peng B, Liao P, Jiang Y. A Meta-Analysis to Revisit the Property-Aggregation Relationships of Carbon Nanomaterials: Experimental Observations versus Predictions of the DLVO Theory. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:7127-7138. [PMID: 38512061 DOI: 10.1021/acs.langmuir.4c00274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Contradicting relationships between physicochemical properties of nanomaterials (e.g., size and ζ-potential) and their aggregation behavior have been constantly reported in previous literature, and such contradictions deviate from the predictions of the classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. To resolve such controversies, in this work, we employed a meta-analytic approach to synthesize the data from 46 individual studies reporting the critical coagulation concentration (CCC) of two carbon nanomaterials, namely, graphene oxide (GO) and carbon nanotube (CNT). The correlations between CCC and material physicochemical properties (i.e., size, ζ-potential, and surface functionalities) were examined and compared to the theoretical predictions. Results showed that the CCC of electrostatically stabilized carbon nanomaterials increased with decreasing nanomaterial size when their hydrodynamic sizes were smaller than ca. 200 nm. This is qualitatively consistent with the prediction of the DLVO theory but with a smaller threshold size than the predicted 2 μm. Above the threshold size, the material ζ-potential can be correlated to CCC for nanomaterials with moderate/low surface charge, in agreement with the DLVO theory. The correlation was not observed for highly charged nanomaterials because of their underestimated surface potential by the ζ-potential. Furthermore, a correlation between the C/O ratio and CCC was observed, where a lower C/O ratio resulted in a higher CCC. Overall, our findings rationalized the inconsistency between experimental observation and theoretical prediction and provided essential insights into the aggregation behavior of nanomaterials in water, which could facilitate their rational design.
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Affiliation(s)
- Bo Peng
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
| | - Peng Liao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 99 Lingcheng West Road, Guiyang 550081, China
| | - Yi Jiang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
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2
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Das S, Chakraborty K, Ghosh D, Pulimi M, Chandrasekaran N, Anand S, Rai PK, Mukherjee A. Systematic assessment of f-MWCNT transport in aqueous medium: the effect of shear and non-shear forces. INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY 2023; 20:6291-6306. [DOI: 10.1007/s13762-022-04295-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/24/2022] [Accepted: 05/18/2022] [Indexed: 10/26/2023]
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Insights on the Dynamics and Toxicity of Nanoparticles in Environmental Matrices. Bioinorg Chem Appl 2022; 2022:4348149. [PMID: 35959228 PMCID: PMC9357770 DOI: 10.1155/2022/4348149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/21/2022] [Accepted: 06/29/2022] [Indexed: 12/29/2022] Open
Abstract
The manufacturing rate of nanoparticles (10–100 nm) is steadily increasing due to their extensive applications in the fabrication of nanoproducts related to pharmaceuticals, cosmetics, medical devices, paints and pigments, energy storage etc. An increase in research related to nanotechnology is also a cause for the production and disposal of nanomaterials at the lab scale. As a result, contamination of environmental matrices with nanoparticles becomes inevitable, and the understanding of the risk of nanoecotoxicology is getting larger attention. In this context, focusing on the environmental hazards is essential. Hence, this manuscript aims to review the toxic effects of nanoparticles on soil, water, aquatic, and terrestrial organisms. The effects of toxicity on vertebrates, invertebrates, and plants and the source of exposure, environmental and biological dynamics, and the adverse effects of some nanoparticles are discussed.
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4
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Liu L, Song J, Zhang M, Jiang W. Aggregation and Deposition Kinetics of Polystyrene Microplastics and Nanoplastics in Aquatic Environment. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2021; 107:741-747. [PMID: 33914100 DOI: 10.1007/s00128-021-03239-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 04/14/2021] [Indexed: 06/12/2023]
Abstract
Microplastics (MPs) and nanoplastics (NPs) attract widespread attention due to their final threats to human health. Here, 50 nm and 500 nm polystyrene particles (PS50 and PS500) were selected as the typical NPs and MPs, respectively. Their aggregation kinetics was monitored, and their deposition was investigated on silica and alumina surfaces using quartz crystal microbalance with dissipation monitoring (QCM-D). PS500 has higher critical coagulation concentration (CCC) values than PS50, because of the weaker Brownian diffusion, less particle number and lower collision chance. PS50 has smaller values of critical deposition concentration (CDC) than PS500, indicating the stronger adsorption on silica. Derjaguin-Landau-Verwey-Overbeek (DLVO) calculations explain that PS500 has weaker attachment on silica and slower deposition rate on alumina than PS50. Our results demonstrate that solution chemistry, particle size and mineral surfaces determine the transport and distribution of plastic particles together.
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Affiliation(s)
- Ling Liu
- Environment Research Institute, Shandong University, Qingdao, 266237, China
| | - Jian Song
- Environment Research Institute, Shandong University, Qingdao, 266237, China
| | - Min Zhang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China.
| | - Wei Jiang
- Environment Research Institute, Shandong University, Qingdao, 266237, China.
- Shenzhen Research Institute, Shandong University, Shenzhen, 518057, China.
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5
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Shao Z, Luo S, Liang M, Ning Z, Sun W, Zhu Y, Mo J, Li Y, Huang W, Chen C. Colloidal stability of nanosized activated carbon in aquatic systems: Effects of pH, electrolytes, and macromolecules. WATER RESEARCH 2021; 203:117561. [PMID: 34450463 DOI: 10.1016/j.watres.2021.117561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/08/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Nanosized activated carbon (NAC) is a novel adsorbent with great potential for water reclamation. However, its transport and reactivity in aqueous environments may be greatly affected by its stability against aggregation. This study investigated the colloidal stability of NAC in model aqueous systems with broad background solution chemistries including 7 electrolytes (NaCl, NaNO3, Na2SO4, KCl, CaCl2, MgCl2, and BaCl2), pH 4-9, and 6 macromolecules (humic acid (HA), fulvic acid (FA), cellulose (CEL), bovine serum albumin (BSA), alginate (ALG), and extracellular polymeric substance (EPS)), along with natural water samples collected from pristine to polluted rivers. The results showed that higher solution pH stabilized NAC by raising the critical coagulation concentration from 28 to 590 mM NaCl. Increased cation concentration destabilized NAC by charge screening, with the cationic influence following Ba2+ > Ca2+ > Mg2+ >> Na+ > K+. Its aggregation behavior could be predicted with the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory with a Hamaker constant (ACWC) of 4.3 × 10-20 J. The presence of macromolecules stabilized NAC in NaCl solution and most CaCl2 solution following EPS > BSA > CEL > HA > FA > ALG, due largely to enhanced electrical repulsion and steric hindrance originated from adsorbed macromolecules. However, ALG and HA strongly destabilized NAC via cation bridging at high Ca2+ concentrations. Approximately half of NAC particles remained stably suspended for ∼10 d in neutral freshwater samples. The results demonstrated the complex effects of water chemistry on fate and transport of NAC in aquatic environments.
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Affiliation(s)
- Zhiwei Shao
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Shijie Luo
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Miaoting Liang
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Zengping Ning
- State Key Laboratory of Environmental Geochemistry, Chinese Academy of Sciences, 99 Linchengxi Road, Guiyang 550081, China
| | - Weimin Sun
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; School of Environment, Henan Key Laboratory for Environmental Pollution Control, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007, China
| | - Yujing Zhu
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Juncheng Mo
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Yongtao Li
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Weilin Huang
- Department of Environmental Sciences, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ 08901, United States
| | - Chengyu Chen
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China.
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Voke E, Pinals RL, Goh NS, Landry MP. In Planta Nanosensors: Understanding Biocorona Formation for Functional Design. ACS Sens 2021; 6:2802-2814. [PMID: 34279907 PMCID: PMC10461777 DOI: 10.1021/acssensors.1c01159] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Climate change and population growth are straining agricultural output. To counter these changes and meet the growing demand for food and energy, the monitoring and engineering of crops are becoming increasingly necessary. Nanoparticle-based sensors have emerged in recent years as new tools to advance agricultural practices. As these nanoparticle-based sensors enter and travel through the complex biofluids within plants, biomolecules including proteins, metabolites, lipids, and carbohydrates adsorb onto the nanoparticle surfaces, forming a coating known as the "bio-corona". Understanding these nanoparticle-biomolecule interactions that govern nanosensor function in plants will be essential to successfully develop and translate nanoparticle-based sensors into broader agricultural practice.
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Affiliation(s)
- Elizabeth Voke
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - Rebecca L Pinals
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - Natalie S Goh
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - Markita P Landry
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
- Innovative Genomics Institute (IGI), Berkeley, California 94720, United States
- California Institute for Quantitative Biosciences, QB3, University of California, Berkeley, California 94720, United States
- Chan-Zuckerberg Biohub, San Francisco, California 94158, United States
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7
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Huang Y, Song K, Luo W, Yang J. Adsorption and reduction of Cr(VI) by hydroxylated multiwalled carbon nanotubes: effects of humic acid and surfactants. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:12746-12754. [PMID: 32008189 DOI: 10.1007/s11356-020-07682-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/07/2020] [Indexed: 06/10/2023]
Abstract
The present study investigated the impacts of humic acid (HA) and surfactants (SDBS and CTAB), which were ubiquitously found in the aquatic environments, on the removal of Cr(VI) by the hydroxylated MWCNTs-OH. The results showed that MWCNTs-OH could remove Cr(VI) from aqueous solution via adsorption coupled with reduction, and the kinetics followed the pseudo-first-order model with the rate of 3.5 × 10-3 h-1. In the presence of anionic SDBS, the removal percentage of Cr(VI) was greatly inhibited because the hydrophobic interaction and π-π interaction between SDBS and MWCNTs-OH surfaces not only decreased the adsorption sites for Cr(VI) but also made the surfaces more negatively charged. On the contrary, the existence of cationic CTAB could lead to the surfaces more positively charged, which consequently enhance the electrostatic attraction between Cr(VI) and the surfaces as well as the removal of Cr(VI). Noticeably, the presence of HA could promote the removal of Cr(VI), which was attributed to the reduction of Cr(VI) by the adsorbed HA. The ESR spectra indicated the existence of π-type radicals in HA structure and conduction electrons in MWCNTs-OH, and then the π-π interaction between MWCNTs-OH and adsorbed HA possibly increase the electron-donating ability of HA. Moreover, the promotive effect of HA could be enhanced with the addition of Ca2+. This study was helpful for us to understand the role of MWCNTs-OH in controlling the fate of Cr(VI) when HA and surfactants were present.
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Affiliation(s)
- Yu Huang
- College of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou, 510025, China
| | - Ke Song
- College of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou, 510025, China
| | - Wei Luo
- College of Chemistry and Environmental Sciences, Guangdong Ocean University, Zhanjiang, 524088, People's Republic of China
| | - Jiewen Yang
- College of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou, 510025, China.
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8
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Sousa VS, Ribau Teixeira M. Metal-based engineered nanoparticles in the drinking water treatment systems: A critical review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 707:136077. [PMID: 31863978 DOI: 10.1016/j.scitotenv.2019.136077] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 12/09/2019] [Accepted: 12/09/2019] [Indexed: 06/10/2023]
Abstract
The emergence of nanotechnologically-enabled materials, compounds or products inevitably leads to engineered nanoparticles (ENPs) released into surface waters. ENPs have already been detected in wastewater streams, drinking water sources and even in tap water at concentrations in the ng/L and μg/L range, making the latter a potential route for humans. The presence of ENPs in raw waters raises concerns over the possibility that ENPs might pose a hazard to the quality and security of drinking water and whether drinking water treatment plants (DWTPs) are prepared to handle this problem. Therefore, it is essential to critically evaluate if ENPs can be effectively removed through water treatment processes to control environmental and human health risks associated with their release. This review includes a summary of the available information on production, presence, potential hazards to human health and environment, and release and behaviour of metal-based ENPs in surface waters and drinking water. In addition, the most extensively studied water treatment processes to remove metal-based ENPs, specifically conventional and advanced processes, are discussed and highlighted in detail. Furthermore, this work identifies the research gaps regarding ENPs removal in DWTPs and discusses future aspects of ENPs in water treatment.
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Affiliation(s)
- Vânia Serrão Sousa
- CENSE, Center for Environmental and Sustainability Research, Portugal; University of Algarve, Faculty of Sciences and Technology, bldg 7, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Margarida Ribau Teixeira
- CENSE, Center for Environmental and Sustainability Research, Portugal; University of Algarve, Faculty of Sciences and Technology, bldg 7, Campus de Gambelas, 8005-139 Faro, Portugal.
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9
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Liu Y, Hu Y, Yang C, Chen C, Huang W, Dang Z. Aggregation kinetics of UV irradiated nanoplastics in aquatic environments. WATER RESEARCH 2019; 163:114870. [PMID: 31336206 DOI: 10.1016/j.watres.2019.114870] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/12/2019] [Accepted: 07/14/2019] [Indexed: 06/10/2023]
Abstract
Nanoplastics (NPs) derived from degradation of macroplastics and microplastics possess potential threat to aquatic biota and human health. Their fate and transport in aquatic systems are mainly governed by aging processes and aggregation behavior. In this study, we simulated plastic aging process using UV-irradiation and compared the aggregation kinetics of fresh versus aged polystyrene NPs (PSNPs) under aqueous conditions. The results showed that fresh PSNPs had strong negative surface charge and exhibited both reaction- and diffusion-limited aggregation regimes, in agreement with classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Divalent electrolytes were 10-15 times more effective in inducing PSNP aggregation than monovalent electrolytes. The aging process inhibited PSNP aggregation in NaCl solutions by increasing the negative charge on PSNP surface and the organic matter content in solution, while promoted PSNP aggregation in CaCl2 solutions due to interactions between Ca2+ and carboxyl groups formed on aged PSNP surface. Such distinct behaviors were consistent with characterizations by contact angle measurements, potentiometric titration, total organic carbon (TOC) analysis, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Hamaker constants obtained from DLVO fitting decreased from 3.5 × 10-21 J for fresh PSNPs to 1.5 × 10-21 J for aged PSNPs. This study indicated that UV-irradiation plays a vital role in governing the fate, transport, and potential hazards of PSNPs in aquatic environments.
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Affiliation(s)
- Yanjun Liu
- College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Yiben Hu
- College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Chen Yang
- College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China.
| | - Chengyu Chen
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China.
| | - Weilin Huang
- Department of Environmental Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Zhi Dang
- College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
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10
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Engel M, Chefetz B. The missing link between carbon nanotubes, dissolved organic matter and organic pollutants. Adv Colloid Interface Sci 2019; 271:101993. [PMID: 31357138 DOI: 10.1016/j.cis.2019.101993] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/10/2019] [Accepted: 07/15/2019] [Indexed: 01/04/2023]
Abstract
Ternary interactions between carbon nanotubes (CNTs), dissolved organic matter (DOM) and small organic molecules (namely low molecular mass organic pollutants) are of great importance since they can affect the reactivity and fate of all involved compartments in the environment. This review thoroughly assesses existing knowledge on the adsorption of DOM and small organic molecules by CNTs, while giving special attention to (i) the complex nature of DOM, (ii) the ternary rather than binary interactions between CNTs, DOM and the small organic molecules and (iii) the DOM-organic molecule interactions. We discuss in detail the main factors influencing DOM adsorption by CNTs and attempt to differentiate between the role of DOM composition and conformation. We then outline how the presence of DOM influences the adsorption of small organic molecules by CNTs, considering the introduction stage of DOM and the impact of the organic molecule's properties. DOM adsorption by CNTs is highly dependent on its composition and is governed by the size, hydrophobicity and aromaticity of DOM. DOM adsorption was found to alter the assembly of the CNTs, resulting in changes in the distribution of adsorption sites. Small organic molecules may adsorb to residual surface area on the CNTs, to DOM-coating the CNTs or remain in solution, possibly complexed with DOM. This results in their suppressed or enhanced adsorption in comparison to DOM-free media. The physicochemical properties of the organic molecules (hydrophobicity, size, structure and charge) also play a major role in this process. We present knowledge gaps that need clarification such as the extent of DOM desorption from CNTs, the amount of co-adsorbed DOM during competition with small organic molecules for adsorption sites on the CNTs and the behavior of CNTs under realistic conditions. More data generated from experiments using natural DOM rather than dissolved humic substances are required to improve our understanding of the interactions between CNTs and small organic molecules in realistic environmental scenarios. This review provides conclusions and research directions needed to evaluate the nature of interactions between CNTs, DOM and organic pollutants in aquatic systems affected by anthropogenic activities.
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Affiliation(s)
- Maya Engel
- Department of Soil and Water Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel; Earth System Science Department, Stanford University, Stanford, CA 94305, United States.
| | - Benny Chefetz
- Department of Soil and Water Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel
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11
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Song J, Wang Q, Zeng Y, Liu Y, Jiang W. Deposition of protein-coated multi-walled carbon nanotubes on oxide surfaces and the retention in a silicon micromodel. JOURNAL OF HAZARDOUS MATERIALS 2019; 375:107-114. [PMID: 31054527 DOI: 10.1016/j.jhazmat.2019.04.077] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/19/2019] [Accepted: 04/23/2019] [Indexed: 05/09/2023]
Abstract
The aggregation, deposition and porous retention of bovine serum albumin treated multi-walled carbon nanotubes (BSA-MWCNTs) are investigated using dynamic light scattering (DLS), quartz crystal microbalance with dissipation (QCM-D) and 2-dimensional silicon micromodel, respectively. The aggregation of BSA-MWCNTs is consistent with Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The critical coagulation concentration (CCC) is 175 mM NaCl and 2.7 mM CaCl2, suggesting that Ca2+ causes stronger aggregation. The BSA-MWCNT deposition on SiO2 surface is unfavorable with critical deposition concentration (CDC) of 100 mM in NaCl and 0.9 mM in CaCl2. The deposition on the Al2O3 surface is favorable. Deposition rate is dominated by electrostatic forces at low ionic strength (IS), but electrostatic interaction is eliminated when IS is above CDC. Therefore the deposition rate on SiO2 or Al2O3 surface starts decreasing at the CDC point due to the reduced particle diffusion. In micromodel, the amount and position of attached BSA-MWCNTs in pore space can be observed by a microscope. The retention attachment efficiency increases at higher IS. The suspended BSA-MWCNTs approach to the collector through either diffusion or interception. The attached BSA-MWCNTs narrow the pore space and then clog the pore throats. The straining process happens on the clogged pore throats.
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Affiliation(s)
- Jian Song
- Environment Research Institute, Shandong University, Qingdao 266237, China; Shenzhen Research Institute, Shandong University, Shenzhen 518057, China
| | - Qi Wang
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Yuxuan Zeng
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Yuanyuan Liu
- School of Earth Science and Engineering, Nanjing University, Nanjing 210023, China
| | - Wei Jiang
- Environment Research Institute, Shandong University, Qingdao 266237, China; Shenzhen Research Institute, Shandong University, Shenzhen 518057, China.
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12
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Yang W, Shang J, Sharma P, Li B, Liu K, Flury M. Colloidal stability and aggregation kinetics of biochar colloids: Effects of pyrolysis temperature, cation type, and humic acid concentrations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 658:1306-1315. [PMID: 30677992 DOI: 10.1016/j.scitotenv.2018.12.269] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 12/06/2018] [Accepted: 12/18/2018] [Indexed: 06/09/2023]
Abstract
An understanding of biochar colloid aggregation and stability in aqueous environments is critical for assessing biochar fate and mobility in the soil. The aggregation kinetics of wheat straw-derived biochar colloids pyrolyzed at two temperatures 300 and 600 °C (WB300 and WB600 colloids, respectively) were investigated in monovalent and divalent electrolyte solutions in absence/presence of humic acid (HA). Results show that the critical coagulation concentrations (CCCs) of WB300 colloids in NaCl and CaCl2 solutions were 274 and 61.4 mM, which were higher than those (183 mM for NaCl and 38.1 mM for CaCl2) of WB600 colloids. WB300 had more oxygen-containing functional groups than WB600, which induced more negative surface charge on WB300. HA of 5 mg L-1 greatly increased the CCCs of WB300 and WB600 colloids to 1288 and 806 mM in NaCl solutions, but decreased the CCCs to 54.6 and 37.0 mM in CaCl2 solutions because of strong bridging between HA and Ca2+. In CaCl2 solutions with high salt concentrations (near to the CCCs), different HA concentrations caused distinct effects on the aggregation of biochar colloids. The aggregation of biochar colloids was accelerated by HA with the concentration higher than 5 mg L-1 through cation-bridging while the aggregation was inhibited in the presence of <2.5 mg L-1 HA. Our findings show that pyrolysis temperature used for biochar production had a large effect on the aggregation of biochar colloids in the aqueous environment and that cation type and dissolved natural organic matter are controlling variables.
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Affiliation(s)
- Wen Yang
- College of Resources and Environmental Sciences, China Agricultural University, Key Laboratory of Plant-Soil Interactions, Ministry of Education, Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture, Beijing 100193, China
| | - Jianying Shang
- College of Resources and Environmental Sciences, China Agricultural University, Key Laboratory of Plant-Soil Interactions, Ministry of Education, Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture, Beijing 100193, China.
| | - Prabhakar Sharma
- School of Ecology and Environment Studies, Nalanda University, Rajgir, Nalanda, Bihar, India
| | - Baoguo Li
- College of Resources and Environmental Sciences, China Agricultural University, Key Laboratory of Plant-Soil Interactions, Ministry of Education, Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture, Beijing 100193, China
| | - Kesi Liu
- Department of Grassland Science, China Agricultural University, Beijing 100193, China
| | - Markus Flury
- Department of Crop and Soil Sciences, Washington State University, Puyallup, WA 98374, United States
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13
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Lead JR, Batley GE, Alvarez PJJ, Croteau MN, Handy RD, McLaughlin MJ, Judy JD, Schirmer K. Nanomaterials in the environment: Behavior, fate, bioavailability, and effects-An updated review. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:2029-2063. [PMID: 29633323 DOI: 10.1002/etc.4147] [Citation(s) in RCA: 264] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/14/2018] [Accepted: 03/29/2018] [Indexed: 05/21/2023]
Abstract
The present review covers developments in studies of nanomaterials (NMs) in the environment since our much cited review in 2008. We discuss novel insights into fate and behavior, metrology, transformations, bioavailability, toxicity mechanisms, and environmental impacts, with a focus on terrestrial and aquatic systems. Overall, the findings were that: 1) despite substantial developments, critical gaps remain, in large part due to the lack of analytical, modeling, and field capabilities, and also due to the breadth and complexity of the area; 2) a key knowledge gap is the lack of data on environmental concentrations and dosimetry generally; 3) substantial evidence shows that there are nanospecific effects (different from the effects of both ions and larger particles) on the environment in terms of fate, bioavailability, and toxicity, but this is not consistent for all NMs, species, and relevant processes; 4) a paradigm is emerging that NMs are less toxic than equivalent dissolved materials but more toxic than the corresponding bulk materials; and 5) translation of incompletely understood science into regulation and policy continues to be challenging. There is a developing consensus that NMs may pose a relatively low environmental risk, but because of uncertainty and lack of data in many areas, definitive conclusions cannot be drawn. In addition, this emerging consensus will likely change rapidly with qualitative changes in the technology and increased future discharges. Environ Toxicol Chem 2018;37:2029-2063. © 2018 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
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Affiliation(s)
- Jamie R Lead
- Center for Environmental Nanoscience and Risk, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA
| | - Graeme E Batley
- Centre for Environmental Contaminants Research, CSIRO Land and Water, Kirrawee, New South Wales, Australia
| | - Pedro J J Alvarez
- Department of Civil and Environmental Engineering, Rice University, Houston, Texas, USA
| | | | | | | | - Jonathan D Judy
- Soil and Water Sciences Department, University of Florida, Gainesville, Florida, USA
| | - Kristin Schirmer
- Department of Environmental Toxicology, Swiss Federal Institute of Aquatic Science and Technology, Eawag, Dübendorf, Switzerland
- School of Architecture, Civil and Environmental Engineering, Federal Institute of Technology Lausanne, Lausanne, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology Zürich, Zürich, Switzerland
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14
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Li S, Liu H, Gao R, Abdurahman A, Dai J, Zeng F. Aggregation kinetics of microplastics in aquatic environment: Complex roles of electrolytes, pH, and natural organic matter. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 237:126-132. [PMID: 29482018 DOI: 10.1016/j.envpol.2018.02.042] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/13/2018] [Accepted: 02/13/2018] [Indexed: 05/06/2023]
Abstract
Microplastics are an emerging contaminants of concern in aquatic environments. The aggregation behaviors of microplastics governing their fate and ecological risks in aquatic environments is in need of evaluation. In this study, the aggregation behavior of polystyrene microspheres (micro-PS) in aquatic environments was systematically investigated over a range of monovalent and divalent electrolytes with and without natural organic matter (i.e., Suwannee River humic acid (HA)), at pH 6.0, respectively. The zeta potentials and hydrodynamic diameters of micro-PS were measured and the subsequent aggregation kinetics and attachment efficiencies (α) were calculated. The aggregation kinetics of micro-PS exhibited reaction- and diffusion-limited regimes in the presence of monovalent or divalent electrolytes with distinct critical coagulation concentration (CCC) values, followed the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The CCC values of micro-PS were14.9, 13.7, 14.8, 2.95 and 3.20 mM for NaCl, NaNO3, KNO3, CaCl2 and BaCl2, respectively. As expected, divalent electrolytes (i.e., CaCl2 and BaCl2) had stronger influence on the aggregation behaviors of micro-PS as compared to monovalent electrolytes (i.e., NaCl, NaNO3 and KNO3). HA enhanced micro-PS stability and shifted the CCC values to higher electrolyte concentrations for all types of electrolytes. The CCC values of micro-PS were lower than reported carbonaceous nanoparticles CCC values. The CCC[Ca2+]/CCC [Na+] ratios in the absence and presence of HA at pH 6.0 were proportional to Z-2.34 and Z-2.30, respectively. These ratios were in accordance with the theoretical Schulze-Hardy rule, which considers that the CCC is proportional to z-6-z-2. These results indicate that the stability of micro-PS in the natural aquatic environment and the possibility of significant aqueous transport of micro-PS.
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Affiliation(s)
- Shuocong Li
- School of Chemistry, Sun Yat-sen University, Guangdong, Guangzhou, 510275, China
| | - Hong Liu
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Rui Gao
- School of Chemistry, Sun Yat-sen University, Guangdong, Guangzhou, 510275, China
| | - Abliz Abdurahman
- School of Chemistry, Sun Yat-sen University, Guangdong, Guangzhou, 510275, China
| | - Juan Dai
- School of Chemistry, Sun Yat-sen University, Guangdong, Guangzhou, 510275, China
| | - Feng Zeng
- School of Chemistry, Sun Yat-sen University, Guangdong, Guangzhou, 510275, China.
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