601
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Akhavan O, Abdolahad M, Abdi Y, Mohajerzadeh S. Silver nanoparticles within vertically aligned multi-wall carbon nanotubes with open tips for antibacterial purposes. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c0jm02395g] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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602
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Feng H, Qian Z, Wang C, Chen C, Chen J. Tuning the energy barrier of water exchange reactions on Al(iii) by interaction with the single-walled carbon nanotubes. Dalton Trans 2011; 40:4183-9. [DOI: 10.1039/c0dt01582b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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603
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Electrochemical fabrication and potential-enhanced luminescence of [Ru(bpy)2tatp]2+ incorporating DNA-stabilized single-wall carbon nanotubes on an indium tin oxide electrode. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2010.10.064] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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604
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Liu Y, Su G, Zhang B, Jiang G, Yan B. Nanoparticle-based strategies for detection and remediation of environmental pollutants. Analyst 2011; 136:872-7. [DOI: 10.1039/c0an00905a] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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605
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Girão EC, Fagan SB, Zanella I, Filho AGS. Nicotine adsorption on single wall carbon nanotubes. JOURNAL OF HAZARDOUS MATERIALS 2010; 184:678-683. [PMID: 20869167 DOI: 10.1016/j.jhazmat.2010.08.091] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 08/20/2010] [Accepted: 08/23/2010] [Indexed: 05/29/2023]
Abstract
This work reports a theoretical study of nicotine molecules interacting with single wall carbon nanotubes (SWCNTs) through ab initio calculations within the framework of density functional theory (DFT). Different adsorption sites for nicotine on the surface of pristine and defective (8,0) SWCNTs were analyzed and the total energy curves, as a function of molecular position relative to the SWCNT surface, were evaluated. The nicotine adsorption process is found to be energetically favorable and the molecule-nanotube interaction is intermediated by the tri-coordinated nitrogen atom from the nicotine. It is also predicted the possibility of a chemical bonding between nicotine and SWCNT through the di-coordinated nitrogen.
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Affiliation(s)
- Eduardo C Girão
- Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Campus do Pici, 60455-900 Fortaleza, Ceará, Brazil
| | - Solange B Fagan
- Área de Ciências Tecnológicas, Centro Universitário Franciscano - UNIFRA, 97010-032 Santa Maria, RS, Brazil
| | - Ivana Zanella
- Área de Ciências Tecnológicas, Centro Universitário Franciscano - UNIFRA, 97010-032 Santa Maria, RS, Brazil
| | - Antonio G Souza Filho
- Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Campus do Pici, 60455-900 Fortaleza, Ceará, Brazil.
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606
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Abstract
Aqueous systems represent a likely carrier for manufactured nanoparticles upon their introduction into the natural environment. Their behavior in water, and in turn the risk that is posed by these materials to environmental and human communities, is a top concern. In terms of risk assessment, nanoparticle exposure to organisms is largely driven by their dispersion and behavior in aqueous systems, while their potential hazard, although not always well understood, is often related to their surface speciation. Both of these characteristics arise from the reactions that occur at the solid/liquid interface. The objective of this article is to establish the current state of the science with regard to the possible changes in surface properties and/or behavior of manufactured nanoparticles in different aqueous solutions of model and inorganic composition. The general reactions occurring at the nanoparticle/water interface, or between nanoparticles themselves, are first introduced. Following this, metal oxides, pure metals and carbon nanoparticles are considered on a case-by-case basis.
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Affiliation(s)
- Jérôme Labille
- CEREGE, CNRS & Aix-Marseille University, Europole Méditerranéen de l'Arbois, BP80, 13545 Aix en Provence cedex 04, France.
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607
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Ji L, Chen W, Bi J, Zheng S, Xu Z, Zhu D, Alvarez PJ. Adsorption of tetracycline on single-walled and multi-walled carbon nanotubes as affected by aqueous solution chemistry. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2010; 29:2713-9. [PMID: 20836069 DOI: 10.1002/etc.350] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 07/15/2010] [Accepted: 08/02/2010] [Indexed: 05/08/2023]
Abstract
Carbon nanotubes have shown great potential as effective adsorbents for hydrophobic organic contaminants in water treatment. The present study investigated the influence of aqueous solution chemistry on the adsorption of tetracycline to carbon nanotubes. Specifically, the effects of ionic strength (NaCl and CaCl(2) ) and presence of Cu(2+) ion (7.5 mg/L) or dissolved soil or coal humic acids (50 mg/L) on adsorption of tetracycline to single-walled carbon nanotubes (SWNT), multi-walled carbon nanotubes (MWNT), and nonporous pure graphite as a model of the graphite surface were systematically estimated. The presence of humic acids suppressed tetracycline adsorption on graphite and MWNT prominently, with stronger effects observed on graphite, but only slightly affected tetracycline adsorption on SWNT. The relatively large humic acid components could not readily access the small interstitial spaces of SWNT and thus were less competitive with tetracycline adsorption. The presence of Cu(2+) ion increased tetracycline adsorption to both SWNT and MWNT through the mechanism of cation bridging, with much larger effects observed on MWNT. This was probably because when compared with the Cu(2+) ions complexed on the surface of SWNT, those on the surface of MWNT having larger mesoporous interstices were more accessible to the relatively bulky tetracycline molecule. Increasing the ionic strength from 10 mM to 100 mM decreased tetracycline adsorption on both SWNT and MWNT, which was attributed to electronic shielding of the negatively charged surface sites. These results show that aqueous solution chemistry is important to tetracycline adsorption on carbon nanotubes.
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Affiliation(s)
- Liangliang Ji
- State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Jiangsu 210093, China
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608
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Liu S, Ng AK, Xu R, Wei J, Tan CM, Yang Y, Chen Y. Antibacterial action of dispersed single-walled carbon nanotubes on Escherichia coli and Bacillus subtilis investigated by atomic force microscopy. NANOSCALE 2010; 2:2744-2750. [PMID: 20877897 DOI: 10.1039/c0nr00441c] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Single-walled carbon nanotubes (SWCNTs) exhibit strong antibacterial activities. Direct contact between bacterial cells and SWCNTs may likely induce cell damages. Therefore, the understanding of SWCNT-bacteria interactions is essential in order to develop novel SWCNT-based materials for their potential environmental, imaging, therapeutic, and military applications. In this preliminary study, we utilized atomic force microscopy (AFM) to monitor dynamic changes in cell morphology and mechanical properties of two typical bacterial models (gram-negative Escherichia coli and gram-positive Bacillus subtilis) upon incubation with SWCNTs. The results demonstrated that individually dispersed SWCNTs in solution develop nanotube networks on the cell surface, and then destroy the bacterial envelopes with leakage of the intracellular contents. The cell morphology changes observed on air dried samples are accompanied by an increase in cell surface roughness and a decrease in surface spring constant. To mimic the collision between SWCNTs and cells, a sharp AFM tip of 2 nm was chosen to introduce piercings on the cell surface. No clear physical damages were observed if the applied force was below 10 nN. Further analysis also indicates that a single collision between one nanotube and a bacterial cell is unlikely to introduce direct physical damage. Hence, the antibacterial activity of SWCNTs is the accumulation effect of large amount of nanotubes through interactions between SWCNT networks and bacterial cells.
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Affiliation(s)
- Shaobin Liu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459
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609
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Tian X, Zhou S, Zhang Z, He X, Yu M, Lin D. Metal impurities dominate the sorption of a commercially available carbon nanotube for Pb(II) from water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:8144-8149. [PMID: 20919734 DOI: 10.1021/es102156u] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Numerous studies suggested carbon nanotubes (CNTs) as a type of promising sorbent for heavy metals from water and explained the sorption mechanism mainly by oxygen-containing functional groups on CNT surfaces but neglected the potential role of metal catalyst residues in CNTs. This is a first study showing that metal impurities could dominate the sorption of one type of commercially available CNTs (P-CNTs) for Pb(II) from water, which will help to understand and guide environmental applications of CNTs as a sorbent. Sorption capacity of P-CNTs (27.3 mg g(-1)) for Pb(II) was much higher than that of the water-washed P-CNTs (W-CNTs, 4.7 mg g(-1)). SEM-EDS and ICP-MS analyses showed that both P-CNTs and W-CNTs contained metal impurities (mainly Co and Mo) which released into the solutions during the sorption, especially P-CNTs. XAFS examination and precipitation experiments demonstrated that PbMoO(4) formation between Pb(II) and CNT-released MoO(4)(2-) and subsequent precipitation in the sorptive solutions was the dominant mechanism for the apparent sorption of Pb(II) by P-CNTs.
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Affiliation(s)
- Xiaoli Tian
- Department of Environmental Science, Zhejiang University, Hangzhou 310028, China
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610
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Upadhyayula VK, Gadhamshetty V. Appreciating the role of carbon nanotube composites in preventing biofouling and promoting biofilms on material surfaces in environmental engineering: A review. Biotechnol Adv 2010; 28:802-16. [DOI: 10.1016/j.biotechadv.2010.06.006] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 05/30/2010] [Accepted: 06/17/2010] [Indexed: 10/19/2022]
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611
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Hussain CM, Mitra S. Micropreconcentration units based on carbon nanotubes (CNT). Anal Bioanal Chem 2010; 399:75-89. [DOI: 10.1007/s00216-010-4194-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 08/27/2010] [Accepted: 09/02/2010] [Indexed: 11/24/2022]
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612
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Ahmad T, Rafatullah M, Ghazali A, Sulaiman O, Hashim R, Ahmad A. Removal of pesticides from water and wastewater by different adsorbents: a review. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2010; 28:231-271. [PMID: 21069614 DOI: 10.1080/10590501.2010.525782] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this review article, the use of various low-cost adsorbents for the removal of pesticides from water and wastewater has been reviewed. Pesticides may appear as pollutants in water sources, having undesirable impacts to human health because of their toxicity, carcinogenicity, and mutagenicity or causing aesthetic problems such as taste and odors. These pesticides pollute the water stream and it can be removed very effectively using different low-cost adsorbents. It is evident from a literature survey of about 191 recently published papers that low-cost adsorbents have demonstrated outstanding removal capabilities for pesticides.
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Affiliation(s)
- Tanweer Ahmad
- School of Industrial Technology, Universiti Sains Malaysia, Malaysia
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613
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Vecitis CD, Zodrow KR, Kang S, Elimelech M. Electronic-structure-dependent bacterial cytotoxicity of single-walled carbon nanotubes. ACS NANO 2010; 4:5471-9. [PMID: 20812689 DOI: 10.1021/nn101558x] [Citation(s) in RCA: 271] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Single-walled carbon nanotubes (SWNTs) have been previously observed to be strong antimicrobial agents, and SWNT coatings can significantly reduce biofilm formation. However, the SWNT antimicrobial mechanism is not fully understood. Previous studies on SWNT cytotoxicity have concluded that membrane stress (i.e., direct SWNT-bacteria contact resulting in membrane perturbation and the release of intracellular contents) was the primary cause of cell death. Gene expression studies have indicated oxidative stress may be active, as well. Here, it is demonstrated for the first time how SWNT electronic structure (i.e., metallic versus semiconducting) is a key factor regulating SWNT antimicrobial activity. Experiments were performed with well-characterized SWNTs of similar length and diameter but varying fraction of metallic nanotubes. Loss of Escherichia coli viability was observed to increase with an increasing fraction of metallic SWNTs. Time-dependent cytotoxicity measurements indicated that in all cases the majority of the SWNT antimicrobial action occurs shortly after (<15 min) bacteria-SWNT contact. The SWNT toxicity mechanism was investigated by in vitro SWNT-mediated oxidation of glutathione, a common intracellular thiol that serves as an antioxidant and redox state mediator. The extent of glutathione oxidation was observed to increase with increasing fraction of metallic SWNTs, indicating an elevated role of oxidative stress. Scanning electron microscopy images of E. coli in contact with the SWNTs demonstrated electronic structure-dependent morphological changes consistent with cytotoxicity and glutathione oxidation results. A three-step SWNT antimicrobial mechanism is proposed involving (i) initial SWNT-bacteria contact, (ii) perturbation of the cell membrane, and (iii) electronic structure-dependent bacterial oxidation.
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Affiliation(s)
- Chad D Vecitis
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520-8286, USA.
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614
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Brady-Estévez AS, Schnoor MH, Vecitis CD, Saleh NB, Elimelech M. Multiwalled carbon nanotube filter: improving viral removal at low pressure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14975-82. [PMID: 20795662 DOI: 10.1021/la102783v] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The effective removal of viruses by a multiwalled carbon nanotube (MWNT) filter is demonstrated over a range of solution chemistries. MS2 bacteriophage viral removal by the MWNT filter was between 1.5 and 3 log higher than that observed with a recently reported single-walled carbon nanotube (SWNT) filter when examined under similar loadings (0.3 mg/cm(2)) of carbon nanotubes (CNTs). The greater removal of viruses by the MWNT filter is attributed to a more uniform CNT-filter matrix that allows effective removal of viruses by physicochemical (depth) filtration. Viral removal by the MWNT filter was examined under a broad range of water compositions (ionic strength, monovalent and divalent salts, solution pH, natural organic matter, alginate, phosphate, and bicarbonate) and filter approach velocities (0.0016, 0.0044, and 0.0072 cm/s). Log viral removal increased as the fluid approach velocity decreased, exhibiting a dependence on approach velocity in agreement with colloid filtration theory for Brownian particles. Viral removal improved with increasing ionic strength (NaCl), from 5.06 log removal at 1 mM NaCl to greater than 6.56 log removal at 100 mM NaCl. Addition of calcium ions also enhanced viral removal, but the presence of magnesium ions resulted in a decrease in viral removal. Solution pH also played an important role in viral removal, with log removals of 8.13, 5.38, and 4.00 being documented at solution pH values of 3.0, 5.5, and 9.0, respectively. Dissolved natural organic matter (NOM) had a negligible effect on viral removal at low concentration (1 mg/L), but higher concentrations of NOM significantly reduced the viral removal by the MWNT filter, likely due to steric repulsion. Addition of alginate (model polysaccharide) also caused a marked decrease in viral removal by the MWNT filter. This highly scalable MWNT-filter technology at gravity-driven pressures presents new, cost-effective options for point-of-use filters for viral removal.
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Affiliation(s)
- Anna S Brady-Estévez
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520-8286, USA
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615
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Abstract
As world water demand continues to grow there is a critical need to develop sustainable water treatment solutions. This chapter describes the potential for nanomaterials to improve the sustainability of water treatment. Nanomaterial-driven advances in disinfection, oxidation, membrane separation and groundwater remediation are discussed with a view towards their potential to improve existing technologies. Disinfection technologies include oligodynamic processes with silver nanoparticles to effectively inactivate microorganisms without disinfection byproducts being formed. Oxidation technologies include metal oxide semiconductors and fullerene-based sensitisers acting as light-driven catalysts. Membrane separation processes include the embedding of materials such as zeolites, carbon nanotubes and metal oxides to improve selectivity and reduce fouling. Remediation technologies include iron particles designed to target and transform waste compounds in situ. These and other emerging water treatment technologies must be assessed with life-cycle analysis to determine the full materials and embodied energy costs of acquiring raw materials, manufacturing, use and end of life for the materials contained within each process. These costs must be weighed against the potential benefits for water treatment to determine their sustainability.
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616
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Ji L, Shao Y, Xu Z, Zheng S, Zhu D. Adsorption of monoaromatic compounds and pharmaceutical antibiotics on carbon nanotubes activated by KOH etching. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:6429-6436. [PMID: 20704245 DOI: 10.1021/es1014828] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The relatively low surface area and micropore volume of carbon nanotubes limit their potential application as effective adsorbents for hydrophobic organic contaminants. In this study, KOH dry etching was explored to prepare activated single-walled carbon nanotubes (SWNT) and multiwalled carbon nanotubes (MWNT) for adsorption of model monoaromatic compounds (phenol and nitrobenzene) and pharmaceutical antibiotics (sulfamethoxazole, tetracycline, and tylosin) in aqueous solutions. With activation, the specific surface area was increased from 410.7 m(2)/g to 652.8 m(2)/g for SWNT and from 157.3 m(2)/g to 422.6 m(2)/g for MWNT, and substantial pore volumes were created for the activated samples. Consistently, adsorption of the test solutes was enhanced 2-3 times on SWNT and 3-8 times on MWNT. Moreover, the activated carbon nanotubes showed improved adsorption reversibility for the selected monoaromatics, as compared with the pristine counterparts, which was attributed to the more interconnected pore structure and less pore deformation of the activated adsorbents. This is the first study on the adsorption/desorption of aqueous organic contaminants by KOH-activated carbon nanotubes. The findings indicate that KOH etching is a useful activation method to improve the adsorption affinity and adsorption reversibility of organic contaminants on carbon nanotubes.
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Affiliation(s)
- Liangliang Ji
- State Key Laboratory of Pollution Control and Resource Reuse, and School of the Environment, Nanjing University, Jiangsu 210093, PR China
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617
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Chandra V, Park J, Chun Y, Lee JW, Hwang IC, Kim KS. Water-dispersible magnetite-reduced graphene oxide composites for arsenic removal. ACS NANO 2010; 4:3979-86. [PMID: 20552997 DOI: 10.1021/nn1008897] [Citation(s) in RCA: 947] [Impact Index Per Article: 67.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Magnetite-graphene hybrids have been synthesized via a chemical reaction with a magnetite particle size of approximately 10 nm. The composites are superparamagnetic at room temperature and can be separated by an external magnetic field. As compared to bare magnetite particles, the hybrids show a high binding capacity for As(III) and As(V), whose presence in the drinking water in wide areas of South Asia has been a huge problem. Their high binding capacity is due to the increased adsorption sites in the M-RGO composite which occurs by reducing the aggregation of bare magnetite. Since the composites show near complete (over 99.9%) arsenic removal within 1 ppb, they are practically usable for arsenic separation from water.
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Affiliation(s)
- Vimlesh Chandra
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, Korea
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618
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Kim J, Van der Bruggen B. The use of nanoparticles in polymeric and ceramic membrane structures: review of manufacturing procedures and performance improvement for water treatment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2010; 158:2335-2349. [PMID: 20430495 DOI: 10.1016/j.envpol.2010.03.024] [Citation(s) in RCA: 335] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 02/06/2010] [Accepted: 03/23/2010] [Indexed: 05/29/2023]
Abstract
Membrane separations are powerful tools for various applications, including wastewater treatment and the removal of contaminants from drinking water. The performance of membranes is mainly limited by material properties. Recently, successful attempts have been made to add nanoparticles or nanotubes to polymers in membrane synthesis, with particle sizes ranging from 4 nm up to 100 nm. Ceramic membranes have been fabricated with catalytic nanoparticles for synergistic effects on the membrane performance. Breakthrough effects that have been reported in the field of water and wastewater treatment include fouling mitigation, improvement of permeate quality and flux enhancement. Nanomaterials that have been used include titania, alumina, silica, silver and many others. This paper reviews the role of engineered nanomaterials in (pressure driven) membrane technology for water treatment, to be applied in drinking water production and wastewater recycling. Benefits and drawbacks are described, which should be taken into account in further studies on potential risks related to release of nanoparticles into the environment.
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Affiliation(s)
- Jeonghwan Kim
- Department of Environmental Engineering, INHA University, Nam-gu, Yonghyun-dong 253, Incheon 402-751, Republic of Korea
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619
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Brady-Estévez AS, Nguyen TH, Gutierrez L, Elimelech M. Impact of solution chemistry on viral removal by a single-walled carbon nanotube filter. WATER RESEARCH 2010; 44:3773-80. [PMID: 20569966 DOI: 10.1016/j.watres.2010.04.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 04/10/2010] [Accepted: 04/22/2010] [Indexed: 05/21/2023]
Abstract
This study investigates the effectiveness of a single-walled carbon nanotube (SWNT) filter for removal of viruses from water. MS2 bacteriophage viral removal was examined over a range of environmentally relevant solution chemistries, spanning various ionic strengths, monovalent and divalent salts, pH, and natural organic matter (NOM) concentrations. Viral removal by the SWNT filter was governed by physicochemical (depth) filtration. The removal of viruses increased at higher ionic strengths (NaCl) due to suppression of repulsive electrostatic interactions between viruses and SWNTs. Addition of divalent salts, however, had varying impacts. While CaCl(2) increased virus removal, likely due to complexation of calcium ions to viral surfaces, addition of MgCl(2) reduced viral removal by the SWNT filter. Solution pH also had significant impact on viral removal as the interactions between viral particles and SWNTs changed from attractive below the virus isoelectric point (about pH 3.9) to repulsive at higher pH. Suwannee River NOM was shown to be detrimental to filter viral removal. Reduction of viral removal by NOM was attributed to adsorption of NOM macromolecules to viruses and SWNTs, thereby resulting in steric repulsive forces. Modifications of the filter to incorporate thicker SWNT layers mitigate the negative impacts of NOM on filter performance. This study has shown that while it is possible to attain high levels of viral removal over a broad range of solution chemistries, the extent of viral removal will be highly dependent on the specific solution chemistry of the treated water.
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Affiliation(s)
- Anna S Brady-Estévez
- Department of Chemical Engineering, Environmental Engineering Program, Yale University, New Haven, CT 06520, USA
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620
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Wang Z, Lee YH, Wu B, Horst A, Kang Y, Tang YJ, Chen DR. Anti-microbial activities of aerosolized transition metal oxide nanoparticles. CHEMOSPHERE 2010; 80:525-529. [PMID: 20478610 DOI: 10.1016/j.chemosphere.2010.04.047] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 04/16/2010] [Accepted: 04/20/2010] [Indexed: 05/29/2023]
Abstract
This study used the electrospray method to create airborne droplets of metal oxide nanoparticles (NPs) and examined their anti-microbial activities, employing Escherichia coli as a model microbial species. We tested the anti-microbial activities of six metal oxide NPs (NiO, ZnO, Fe(2)O(3), Co(3)O(4), CuO, and TiO(2)) in both an aqueous culture medium and an aerosol exposure mode (spraying the particles directly onto the cell surface). In the aqueous medium, the both NPs and stressed E. coli cells severely aggregated. Only NiO NPs (>20 mgL(-1)) showed significant growth inhibition of E. coli ( approximately 30%). In contrast to aqueous exposure, where the direct interactions between NPs and bacteria were limited, aerosol exposure of three metal oxide NPs to E. coli enhanced NP toxicity to cells and dramatically reduced cellular viability. Electrospraying NiO, CuO, or ZnO NPs (20 nm, 20 microg, in 10 min) reduced the total number of living E. coli by more than 88%, 77% and 71%, respectively (compared to the control experiments). However, TiO(2), Co(3)O(4), and Fe(2)O(3) NPs showed no significant antibacterial activities in either the aqueous exposure mode or the aerosol exposure mode. The above observations suggest the potential application of electrosprayed metal oxide NPs to disinfect airborne pathogens.
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Affiliation(s)
- Zhipeng Wang
- Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO 63130, USA
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621
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Sheng GD, Shao DD, Ren XM, Wang XQ, Li JX, Chen YX, Wang XK. Kinetics and thermodynamics of adsorption of ionizable aromatic compounds from aqueous solutions by as-prepared and oxidized multiwalled carbon nanotubes. JOURNAL OF HAZARDOUS MATERIALS 2010; 178:505-16. [PMID: 20153109 DOI: 10.1016/j.jhazmat.2010.01.110] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 01/19/2010] [Accepted: 01/21/2010] [Indexed: 05/21/2023]
Abstract
The adsorption of 1-naphthylamine, 1-naphthol and phenol on as-prepared and oxidized multiwalled carbon nanotubes (MWCNTs) has been investigated. The results illustrated that both as-prepared and oxidized MWCNTs showed high adsorption capacity for the three ionizable aromatic compounds (IACs) studied. Oxidation of MWCNTs increased the surface area and the pore volume, and introduced oxygen-containing functional groups to the surfaces of MWCNTs, which depressed the adsorption of IACs on MWCNTs. Both Langmuir and Freundlich models described the adsorption isotherms very well and the adsorption thermodynamic parameters (DeltaG degrees, DeltaH degrees and DeltaS degrees) were measured. The adsorption for 1-naphthylamine, 1-naphthol and phenol is general spontaneous and thermodynamically favorable. The adsorption of phenol is an exothermic process, whereas the adsorption of 1-naphthylamine and 1-naphthol is an endothermic process. Results of this work are of great significance for the environmental application of MWCNTs for the removal of IACs from large volume of aqueous solutions.
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Affiliation(s)
- G D Sheng
- Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, PR China
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622
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Sheng G, Li J, Shao D, Hu J, Chen C, Chen Y, Wang X. Adsorption of copper(II) on multiwalled carbon nanotubes in the absence and presence of humic or fulvic acids. JOURNAL OF HAZARDOUS MATERIALS 2010; 178:333-340. [PMID: 20153111 DOI: 10.1016/j.jhazmat.2010.01.084] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 01/18/2010] [Accepted: 01/19/2010] [Indexed: 05/28/2023]
Abstract
The adsorption of Cu(II) on multiwalled carbon nanotubes (MWCNTs) as a function of pH and ionic strength in the absence and presence of humic acid (HA) or fulvic acid (FA) was studied using batch technique. The results indicated that the adsorption is strongly dependent on pH but independent of ionic strength. A positive effect of HA/FA on Cu(II) adsorption was found at pH <7.5, whereas a negative effect was observed at pH >7.5. The adsorption isotherms can be described better by the Freundlich model than by the Langmuir model in the absence and presence of HA/FA. Adsorption isotherms of Cu(II) at higher initial HA/FA concentrations are higher than those of Cu(II) at lower FA/HA concentrations. The thermodynamic data calculated from temperature-dependent adsorption isotherms suggested that the adsorption was spontaneous and enhanced at higher temperature. Results of this work suggest that MWCNTs may be a promising candidate for the removal of heavy metal ions from aqueous solutions.
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Affiliation(s)
- Guodong Sheng
- School of Nuclear Science and Engineering, North China Electric Power University, Beijing, 102206, PR China
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623
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Konstantinou M, Pashalidis I. Competitive sorption of Cu(II) and Eu(III) ions on olive-cake carbon in aqueous solutions—a potentiometric study. ADSORPTION 2010. [DOI: 10.1007/s10450-010-9218-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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624
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Yang K, Xing B. Adsorption of Organic Compounds by Carbon Nanomaterials in Aqueous Phase: Polanyi Theory and Its Application. Chem Rev 2010; 110:5989-6008. [DOI: 10.1021/cr100059s] [Citation(s) in RCA: 649] [Impact Index Per Article: 46.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Kun Yang
- Department of Environmental Science, Zhejiang University, Hangzhou 310028, China, and Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, Massachusetts 01003
| | - Baoshan Xing
- Department of Environmental Science, Zhejiang University, Hangzhou 310028, China, and Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, Massachusetts 01003
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625
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Ong YT, Ahmad AL, Zein SHS, Tan SH. A review on carbon nanotubes in an environmental protection and green engineering perspective. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2010. [DOI: 10.1590/s0104-66322010000200002] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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626
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Yang K, Wu W, Jing Q, Jiang W, Xing B. Competitive adsorption of naphthalene with 2,4-dichlorophenol and 4-chloroaniline on multiwalled carbon nanotubes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:3021-3027. [PMID: 20201557 DOI: 10.1021/es100018a] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Competitive adsorption between nonpolar organic compounds and polar ionic organic compounds (IOCs) on carbon nanotubes (CNTs) is essential for application of CNTs as superior sorbents and for environmental risk assessment of both CNTs and organic contaminants. It was observed in this study that adsorption of neutral and dissociated species of polar 2,4-dichlorophenol (DCP) and 4-chloroaniline (PCAN) on a multiwalled CNT sample (MWCNT15) can be suppressed by nonpolar naphthalene. Naphthalene adsorption can also be suppressed by neutral DCP/PCAN, but not dissociated DCP/PCAN. Moreover, competition of naphthalene decreased the adsorption affinity of neutral DCP/PCAN, but not their adsorption capacity because of the formation of solute bilayer on MWCNT15. For dissociated DCP/PCAN, naphthalene not only decreased their adsorption affinity but also their adsorption capacity because no solute bilayer was formed. Neutral DCP/PCAN also decreased the adsorption affinity and adsorption capacity of naphthalene. These observations indicate that competitive adsorption of naphthalene with DCP/PCAN depends on the dissociation of DCP/PCAN, as interpreted by (i) the different sites on CNTs for adsorption of organic chemicals (i.e., naphthalene, and the neutral and dissociated species of DCP/PCAN), (ii) the interactions between organic chemicals, and (iii) the interactions of organic chemicals with CNT surface.
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Affiliation(s)
- Kun Yang
- Department of Environmental Science, Zhejiang University, Hangzhou 310028, China.
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627
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Hwang YS, Li Q. Characterizing photochemical transformation of aqueous nC60 under environmentally relevant conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:3008-3013. [PMID: 20337472 DOI: 10.1021/es903713j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Engineered nanomaterials may undergo transformation upon interactions with various environmental factors. In this study, photochemical transformation of aqueous nC60 was investigated under UVA irradiation. nC60 underwent photochemical transformation in the presence of dissolved O2, resulting in surface oxygenation and hydroxylation as demonstrated by XPS and ATR-FTIR analyses. The reaction followed a pseudo-first order rate law with the apparent reaction rate constant of 2.2 x 10(-2) h(-1). However, the core of the nanoparticles remained intact over 21 days of irradiation. Although no mineralization or dissolution of nC60 was observed, experiments using fullerol as a reference fullerene derivative suggested likely dissolution and partial mineralization of nC60 under long-term UVA exposure. Aquatic humic acid reduced nC60 transformation kinetics presumably due to scavenging of reactive oxygen species. Results from this study imply that photochemical transformation is an important factor controlling nC60 physical and chemical properties as well as its fate and transport in the natural aqueous environment. In addition, changes in nC60 surface chemistry drastically reduced C60 extraction efficiency by toluene, suggesting that the existing analytical method for C60 may not be applicable to environmental samples.
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Affiliation(s)
- Yu Sik Hwang
- Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005, USA
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628
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Afonso R, Durão J, Mendes A, Damas A, Gales L. Dipeptide Crystals as Excellent Permselective Materials: Sequential Exclusion of Argon, Nitrogen, and Oxygen. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201000007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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629
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Afonso R, Durão J, Mendes A, Damas A, Gales L. Dipeptide Crystals as Excellent Permselective Materials: Sequential Exclusion of Argon, Nitrogen, and Oxygen. Angew Chem Int Ed Engl 2010; 49:3034-6. [DOI: 10.1002/anie.201000007] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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630
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Xia X, Li Y, Zhou Z, Feng C. Bioavailability of adsorbed phenanthrene by black carbon and multi-walled carbon nanotubes to Agrobacterium. CHEMOSPHERE 2010; 78:1329-1336. [PMID: 20116085 DOI: 10.1016/j.chemosphere.2010.01.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Revised: 01/06/2010] [Accepted: 01/06/2010] [Indexed: 05/28/2023]
Abstract
Carbonaceous sorbents including black carbon (BC) and carbon nanotubes have attracted research attention around the world because of their effects on bioavailability of hydrophobic organic compounds (HOCs) in sediments and soils. In this research, (14)C-labeled and unlabeled phenanthrene were spiked into three artificial sediments: (i) a sediment sample without amorphous organic carbon (OC) and with BC collected from the Yangtze River (BC-YR), (ii) a sediment without OC and with multi-walled carbon nanotubes (MWCNTs), and (iii) a sediment without OC and with fresh wood char. Biodegradation and mineralization of adsorbed phenanthrene by Agrobacterium and XAD-2 assisted abiotic desorption of adsorbed phenanthrene were studied. The results showed that microbes could utilize a fraction of adsorbed phenanthrene by BC and MWCNTs after aging for 21-40d. With aging for 28d, the biodegradation efficiencies of phenanthrene after incubation for 21d were 83.8%, 73.5% and 54.2% for BC-YR, char and MWCNTs, respectively; with aging for 40d, the mineralization rates of (14)C-labeled phenanthrene after incubation for 25d were 38.3%, 25.1% and 24.6%, respectively. The desorption and biodegradation processes showed similar residual concentration of phenanthrene. However, the biodegradation rates were higher than the desorption rates during the fast biodegradation stage, suggesting that bacteria could promote desorption or access and utilize the sorbed phenanthrene. The biodegradation and mineralization efficiencies of phenanthrene associated with MWCNTs were significantly lower than with BC (p<0.01), implying adsorption by MWCNTs may lead to a greater decrease of HOCs bioavailability in the environment.
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Affiliation(s)
- Xinghui Xia
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
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631
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Brar SK, Verma M, Tyagi RD, Surampalli RY. Engineered nanoparticles in wastewater and wastewater sludge--evidence and impacts. WASTE MANAGEMENT (NEW YORK, N.Y.) 2010; 30:504-20. [PMID: 19926463 DOI: 10.1016/j.wasman.2009.10.012] [Citation(s) in RCA: 328] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 09/30/2009] [Accepted: 10/20/2009] [Indexed: 05/24/2023]
Abstract
Nanotechnology has widespread application in agricultural, environmental and industrial sectors ranging from fabrication of molecular assemblies to microbial array chips. Despite the booming application of nanotechnology, there have been serious implications which are coming into light in the recent years within different environmental compartments, namely air, water and soil and its likely impact on the human health. Health and environmental effects of common metals and materials are well-known, however, when the metals and materials take the form of nanoparticles--consequential hazards based on shape and size are yet to be explored. The nanoparticles released from different nanomaterials used in our household and industrial commodities find their way through waste disposal routes into the wastewater treatment facilities and end up in wastewater sludge. Further escape of these nanoparticles into the effluent will contaminate the aquatic and soil environment. Hence, an understanding of the presence, behavior and impact of these nanoparticles in wastewater and wastewater sludge is necessary and timely. Despite the lack of sufficient literature, the present review attempts to link various compartmentalization aspects of the nanoparticles, their physical properties and toxicity in wastewater and wastewater sludge through simile drawn from other environmental streams.
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Affiliation(s)
- Satinder K Brar
- INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec, Canada.
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632
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Liu W, Xu X, Wang Y, He Z, Zhuo N, Huang F, Lin Z. Treatment of Cr(VI)-containing nanowastes via the growth of nanomaterial. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/s11434-009-0716-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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633
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Baccile N, Antonietti M, Titirici MM. One-step hydrothermal synthesis of nitrogen-doped nanocarbons: albumine directing the carbonization of glucose. CHEMSUSCHEM 2010; 3:246-53. [PMID: 19885901 DOI: 10.1002/cssc.200900124] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We present a simple and green one-step pathway towards nitrogen-doped carbon nanostructures with controlled mesoporosity through hydrothermal treatment of glucose in the presence of model proteins. Performing the reaction with different amounts of egg white ovalbumin protein (OvA), carbonaceous nanoparticles or continuous nanosponges with high specific surface areas can be efficiently produced. The nitrogen content of the structures is rather high (up to 8 wt%) and can be kept constant up to 950 degrees C, while oxygen elimination and graphitization of the carbon material occurs. We demonstrate here that sustainable natural resources can be efficiently used in the synthesis of pure high-potential nanomaterials.
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Affiliation(s)
- Niki Baccile
- CNRS UPMC Univ. Paris 06, UMR 7574, Chimie de la Matière Condensée de Paris, 75005, Paris, France
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634
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Gui X, Wei J, Wang K, Cao A, Zhu H, Jia Y, Shu Q, Wu D. Carbon nanotube sponges. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2010; 22:617-21. [PMID: 20217760 DOI: 10.1002/adma.200902986] [Citation(s) in RCA: 656] [Impact Index Per Article: 46.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Affiliation(s)
- Xuchun Gui
- Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, PR China
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635
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Yang K, Jing Q, Wu W, Zhu L, Xing B. Adsorption and conformation of a cationic surfactant on single-walled carbon nanotubes and their influence on naphthalene sorption. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:681-7. [PMID: 20000820 DOI: 10.1021/es902173v] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Surfactants are used in synthesis and dispersion of carbon nanotubes (CNTs) and can thus be released into the environment with CNTs. In this study, it was observed that the coupled release of surfactants and CNTs altered the sorption of organic contaminants on the CNTs. The cationic surfactant, cetylpyridinium chloride (CPC), decreased naphthalene sorption on single-walled carbon nanotubes (SWCNT). In the most dramatic example, the adsorption capacity of naphthalene on SWCNT was reduced from 240 to 61.1 mg/g. The decrease of naphthalene sorption could be largely attributed to the competition of adsorbed CPC cations (i.e., C(21)H(38)N(+)) with naphthalene by occupying the SWCNT surface as surfaces decreased from 737 to 88.9 m(2)/g after the coating of CPC. However, the adsorbed CPC may form hemimicelles and result in a favorable media for naphthalene partition to counteract the decrease in naphthalene sorption. Configuration changes of adsorbed CPC hemimicelles might occur because the naphthalene partition into the adsorbed CPC decreased with the increase of adsorbed CPC. A partition-adsorption model was introduced to describe the partition fraction of naphthalene into adsorbed CPC hemimicelles as well as the adsorption fraction of naphthalene on unoccupied surfaces of SWCNT.
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Affiliation(s)
- Kun Yang
- Department of Environmental Science, Zhejiang University, Hangzhou 310028, China.
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636
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Li H, Gui X, Zhang L, Wang S, Ji C, Wei J, Wang K, Zhu H, Wu D, Cao A. Carbon nanotube sponge filters for trapping nanoparticles and dye molecules from water. Chem Commun (Camb) 2010; 46:7966-8. [DOI: 10.1039/c0cc03290e] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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637
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Shi B, Zhuang X, Yan X, Lu J, Tang H. Adsorption of atrazine by natural organic matter and surfactant dispersed carbon nanotubes. J Environ Sci (China) 2010; 22:1195-1202. [PMID: 21179958 DOI: 10.1016/s1001-0742(09)60238-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The aggregation and dispersion behaviors of carbon nanotubes (CNTs) can regulate the environmental spread and fate of CNTs, as well as the organic pollutants adsorbed onto them. In this study, multi-walled carbon nanotubes (MWNTs) and single-walled carbon nanotubes (SWNTs) were surface modified with humic acids from different sources and with surfactants of different ionic types. The dispersion stability of surface modified CNTs was observed by UV-Vis spectrophotometry. The effect of humic acid and surfactant dispersion on the adsorption of atrazine by CNTs was investigated by batch equilibrium experiments. Both humic acid and surfactant could effectively disperse MWNTs, but not SWNTs, into stable suspensions under the studied conditions. Surface modified CNTs had a greatly reduced capacity for adsorption of atrazine. The inhibitory effect of peat humic acid was relatively stronger than that of soil humic acid, but the two surfactants had a similar inhibitory effect on atrazine adsorption by the two CNT types. Increases in surfactant concentration resulted in rapid decreases in the adsorption of atrazine by CNTs when the surfactant concentration was less than 0.5 critical micelle concentration.
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Affiliation(s)
- Baoyou Shi
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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638
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Su F, Lu C, Hu S. Adsorption of benzene, toluene, ethylbenzene and p-xylene by NaOCl-oxidized carbon nanotubes. Colloids Surf A Physicochem Eng Asp 2010. [DOI: 10.1016/j.colsurfa.2009.10.025] [Citation(s) in RCA: 171] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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639
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Liu S, Wei L, Hao L, Fang N, Chang MW, Xu R, Yang Y, Chen Y. Sharper and faster "nano darts" kill more bacteria: a study of antibacterial activity of individually dispersed pristine single-walled carbon nanotube. ACS NANO 2009; 3:3891-902. [PMID: 19894705 DOI: 10.1021/nn901252r] [Citation(s) in RCA: 305] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
To further our understanding on the antibacterial activity of single-walled carbon nanotubes (SWCNTs), high purity SWCNTs with average diameter of 0.83 nm and (7,5) chirality as dominate (n,m) structure were dispersed in a biocompatible surfactant solution. Ultraviolet-visible-near-infrared radiation absorption spectroscopy was employed to monitor the aggregation of SWCNTs. The results demonstrated that individually dispersed SWCNTs were more toxic than SWCNT aggregates toward bacteria (gram-negative Escherichia coli, Pseudomonas aeruginosa, and gram-positive Staphylococcus aureus, Bacillus subtilis). Individually dispersed SWCNTs can be visualized as numerous moving "nano darts" in the solution, constantly attacking the bacteria; thereby, degrading the bacterial cell integrity and causing the cell death. Controlled experimental results suggested that inhibiting cell growth and oxidative stress were not the major causes responsible for the death of cells. Furthermore, the detrimental effects of Co metal residues (up to 1 mug/mL) on SWCNT samples can be ruled out. Atomic force microscope study conducted in suspension proved that the death rates of bacteria were strongly correlated with their mechanical properties; soft cells were more vulnerable to SWCNT piercing. The antibacterial activity of SWCNTs can be remarkably improved by enhancing the SWCNT physical puncture on bacteria in the following ways: (1) dispersing SWCNTs individually to sharpen the nano darts; (2) increasing SWCNT concentration to raise the population density of nano darts; and (3) elevating the shaking speed of incubation to speed up the nano darts. This study elucidated several factors controlling the antibacterial activity of pristine SWCNTs and it provided an insight in developing strategies that can maximize the SWCNT application potentials while minimizing the health and environment risks.
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Affiliation(s)
- Shaobin Liu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
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640
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Oleszczuk P, Pan B, Xing B. Adsorption and desorption of oxytetracycline and carbamazepine by multiwalled carbon nanotubes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:9167-9173. [PMID: 20000507 DOI: 10.1021/es901928q] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We investigated the adsorption-desorption by multiwalled carbon nanotubes (MWCNTs) of two pharmaceuticals, oxytetracycline (OTC) and carbamazepine (CBZ). The pharmaceuticals demonstrated relatively fast sorption kinetics on MWCNTs. All adsorption isotherms were nonlinear and fit the Polanyi-Manes model (PMM). The single point adsorption coefficient (K) values for OTC were more than 1 order of magnitude higher than those for CBZ on corresponding MWCNTs. The adsorbed volume capacity (Q(0)) and K values of PMM showed a significant relationship with surface areas and the meso- and micropore volume of MWCNTs for both chemicals. Depending on the MWCNT outer diameter, 13.8-25.2% and 62.7-90.6% of initially adsorbed OTC and CBZ, respectively, were desorbed after 200 h. The rate of desorption of both OTC and CBZ depended upon pH and the quantity of initially adsorbed pharmaceuticals, as well as aggregation in the case of OTC.
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Affiliation(s)
- Patryk Oleszczuk
- Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, Massachusetts 01003, USA
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641
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Upadhyayula VKK, Deng S, Mitchell MC, Smith GB. Application of carbon nanotube technology for removal of contaminants in drinking water: a review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2009; 408:1-13. [PMID: 19819525 DOI: 10.1016/j.scitotenv.2009.09.027] [Citation(s) in RCA: 296] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2009] [Revised: 09/11/2009] [Accepted: 09/15/2009] [Indexed: 05/10/2023]
Abstract
Carbon nanotube (CNT) adsorption technology has the potential to support point of use (POU) based treatment approach for removal of bacterial pathogens, natural organic matter (NOM), and cyanobacterial toxins from water systems. Unlike many microporous adsorbents, CNTs possess fibrous shape with high aspect ratio, large accessible external surface area, and well developed mesopores, all contribute to the superior removal capacities of these macromolecular biomolecules and microorganisms. This article provides a comprehensive review on application of CNTs as adsorbent media to concentrate and remove pathogens, NOM, and cyanobacterial (microcystin derivatives) toxins from water systems. The paper also surveys on consideration of CNT based adsorption filters for removal of these contaminants from cost, operational and safety standpoint. Based on the studied literature it appears that POU based CNT technology looks promising, that can possibly avoid difficulties of treating biological contaminants in conventional water treatment plants, and thereby remove the burden of maintaining the biostability of treated water in the distribution systems.
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Affiliation(s)
- Venkata K K Upadhyayula
- Microbiology and Applied Biochemistry Division, Air Force Research Labs, 139 Barnes Drive, Suite II, Tyndall Air Force Base, Panama City, FL 32403, United States.
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642
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Jaisi DP, Elimelech M. Single-walled carbon nanotubes exhibit limited transport in soil columns. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:9161-9166. [PMID: 20000506 DOI: 10.1021/es901927y] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The increased production and commercial use of nanomaterials combined with a lack of regulation to govern their disposal may result in their introduction to soils and ultimately into groundwater systems. In this study, we investigated the transport behavior of carboxyl-functionalized single-walled carbon nanotubes (SWNTs) in columns packed with a natural soil. In general, SWNT deposition (filtration) rate increased with increasing solution ionic strength, with divalent cations (Ca(2+)) being more effective in increasing SWNT retention than monovalent cations (K(+)). However, SWNT deposition rate over a very wide range of monovalent and divalent cation concentrations (0.03 to 100 mM) was relatively high and changed only slightly above 0.3 mM KCl or 0.1 mM CaCl(2). In contrast, filtration of another type of engineered carbon-based nanomaterial, namely aqueous fullerene (C(60)) nanoparticles (radius of 51 nm), was more sensitive to solution ionic strength, displaying lower deposition rate and more effective transport in soil than SWNTs. These observations indicate that physical straining governs SWNT filtration and transport under all the solution chemistries investigated in the present study. It is proposed that SWNT shape and structure, particularly the very large aspect ratio and its highly bundled (aggregated) state in aqueous solutions, as well as the heterogeneity in soil particle size, porosity, and permeability, collectively contribute to straining in flow through soil media. Our results suggest that SWNTs of comparable properties to those used in the present study will not exhibit substantial transport and infiltration in soils because of effective retention by the soil matrix.
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Affiliation(s)
- Deb P Jaisi
- Department of Chemical Engineering, Environmental Engineering Program, Yale University, New Haven, Connecticut 06520-8286, USA
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643
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Hazards and Risks of Engineered Nanoparticles for the Environment and Human Health. SUSTAINABILITY 2009. [DOI: 10.3390/su1041161] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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644
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Liu X, O'Carroll DM, Petersen EJ, Huang Q, Anderson CL. Mobility of multiwalled carbon nanotubes in porous media. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:8153-8158. [PMID: 19924937 DOI: 10.1021/es901340d] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Engineered multiwalled carbon nanotubes (MWCNTs) are the subject of intense research and are expected to gain widespread usage in a broad variety of commercial products. However, concerns have been raised regarding potential environmental and human health risks. The mobility of MWCNTs in porous media is examined in this study using one-dimensional flow-through column experiments under conditions representative of subsurface and drinking water treatment systems. Results demonstrate that pore water velocity strongly influenced MWCNT transport, with high MWCNT mobility at pore water velocities greater than 4.0 m/d. A numerical simulator, which incorporated a newly developed theoretical collector efficiency relationship for MWCNTs in spherical porous media, was developed to model observed column results. The model, which incorporated traditional colloid filtration theory in conjunction with a site-blocking term, yielded good agreement with observed results in quartz sand-packed column experiments. Experiments were also conducted in glass bead-packed columns with the same mean grain size as the quartz sand-packed columns. MWCNTs were more mobile in the glass bead-packed columns.
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Affiliation(s)
- Xueying Liu
- Department of Civil & Environmental Engineering, The University of Western Ontario, London, ON, Canada N6A 5B8
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645
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Chen KL, Elimelech M. Relating colloidal stability of fullerene (C60) nanoparticles to nanoparticle charge and electrokinetic properties. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:7270-6. [PMID: 19848133 DOI: 10.1021/es900185p] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The stability and aggregation kinetics of two different suspensions of fullerene (C60) nanoparticles and their relation to nanoparticle charge (electrokinetic) properties were investigated. The two synthesis methods employed--a solvent exchange method involving sonication of fullerene initially dissolved in toluene and prolonged stirring of bulk fullerene in water--produce negatively charged fullerene nanoparticles. With an increase in electrolyte (KCl) concentration, the electrophoretic mobilities of both fullerene nanoparticles became less negative, while the corresponding aggregation rates increased until maximum rates were reached at their respective critical coagulation concentrations. This behavior is consistent with the classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory for the stability of charged colloidal particles. The nanoparticles prepared by prolonged stirring of bulk fullerene in water were much more stable than those prepared by sonication in toluene, as evident from their significantly higher critical coagulation concentration (166 and 40 mM KCl, respectively). A comparison of the aggregation kinetics with predictions based on DLVO theory yielded the same Hamaker constant (8.5 x 10(-21) J) for both fullerene nanoparticles, indicating that they have the same material composition. Further investigation shows that both fullerene nanoparticles are more negatively charged and stable at higher pH conditions, suggesting that dissociation of surface functional groups contributes to surface charge for both nanoparticles. This hypothesis is further supported by oxidation which occurs on the surface of bulk fullerene that has been exposed to water over a prolonged period of time, as detected through X-ray photoelectron spectroscopy (XPS). However, since both nanoparticles remain negatively charged at pH 2, it is likely that there are other contributing factors to the surface charge of fullerene nanoparticles.
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Affiliation(s)
- Kai Loon Chen
- Department of Geography and Environmental Engineering, Johns Hopkins University, Baltimore, Maryland 21218-2686, USA.
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646
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Chen GC, Shan XQ, Zhou YQ, Shen XE, Huang HL, Khan SU. Adsorption kinetics, isotherms and thermodynamics of atrazine on surface oxidized multiwalled carbon nanotubes. JOURNAL OF HAZARDOUS MATERIALS 2009; 169:912-918. [PMID: 19442439 DOI: 10.1016/j.jhazmat.2009.04.034] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 04/09/2009] [Accepted: 04/09/2009] [Indexed: 05/27/2023]
Abstract
The adsorption kinetics, isotherms and thermodynamic of atrazine on multiwalled carbon nanotubes (MWCNTs) containing 0.85%, 2.16%, and 7.07% oxygen was studied. Kinetic analyses were performed using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The regression results showed that the pseudo-second-order law fit the adsorption kinetics. The calculated thermodynamic parameters indicated that adsorption of atrazine on MWCNTs was spontaneous and exothermic. Standard free energy (DeltaG(0)) became less negative when the oxygen content of MWCNTs increased from 0.85% to 7.07% which is consistent with the low adsorption affinity of MWCNTs for atrazine.
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Affiliation(s)
- Guang-Cai Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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647
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Wang D, Sun L, Liu W, Chang W, Gao X, Wang Z. Photoinduced DNA cleavage by alpha-, beta-, and gamma-cyclodextrin-bicapped C60 supramolecular complexes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:5825-5829. [PMID: 19731683 DOI: 10.1021/es900709p] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Water-soluble supramolecular inclusion complexes of alpha-, beta-, and gamma-cyclodextrin-bicapped C60 (CD/C60) have been investigated for their photoinduced DNA cleavage activities, with the aim to assess the potential health risks of this class of compounds and to understand the effect of host cyclodextrins having different cavity dimensions. Factors such as incubation temperature, irradiation time, and concentration of NADH or CDs/ C60 supramolecular inclusion complexes have been examined. The results show that alpha-, beta-, and gamma-CDs/C60 are all able to cleave double-stranded DNA under visible light irradiation in the presence of NADH. However, a difference in the photoinduced DNA cleavage efficiency is observed, where the cleavage efficiency increases in the order of alpha-, beta-, and gamma-CD/C60. The difference is attributed to the different aggregation behavior of the inclusion complexes in aqueous solution, which is correlated to the cavity dimension of the host cyclodextrin molecules.
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Affiliation(s)
- Deyan Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022, China
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648
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Abstract
In this final chapter a new perspective for the application of QSAR in the nanosciences is discussed. The role of nanomaterials is rapidly increasing in many aspects of everyday life. This is promoting a wide range of research needs related to both the design of new materials with required properties and performing a comprehensive risk assessment of the manufactured nanoparticles. The development of nanoscience also opens new areas for QSAR modelers. We have begun this contribution with a detailed discussion on the remarkable physical–chemical properties of nanomaterials and their specific toxicities. Both these factors should be considered as potential endpoints for further nano-QSAR studies. Then, we have highlighted the status and research needs in the area of molecular descriptors applicable to nanomaterials. Finally, we have put together currently available nano-QSAR models related to the physico-chemical endpoints of nanoparticles and their activity. Although we have observed many problems (i.e., a lack of experimental data, insufficient and inadequate descriptors), we do believe that application of QSAR methodology will significantly support nanoscience in the near future. Development of reliable nano-QSARs can be considered as the next challenging task for the QSAR community.
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649
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Petersen EJ, Pinto RA, Landrum PF, Weber WJ. Influence of carbon nanotubes on pyrene bioaccumulation from contaminated soils by earthworms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:4181-4187. [PMID: 19569349 DOI: 10.1021/es803023a] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Increasing production of and application potentials for carbon nanotubes (CNTs) suggest these materials will enter soil and sediment ecosystems in significant masses in upcoming years. This may result in ecological risks, either from the presence of the CNTs themselves or, given their exceptional sorption capacities, from their effects on the fate and accumulation of concurrently present hydrophobic organic chemicals (HOCs). Here we test the influence of additions of single-walled CNTs (SWNTs) and multi-walled CNTs (MWNTs) to two different pyrene-contaminated soils on uptake of this HOC by earthworms (Eisenia foetida). The effects of nanotube additions to the soils were observed to be CNT concentration dependent, with 0.3 mg nanotubes per gram of soil having no impact, while 3.0 mg/g of SWNTs or MWNTs substantially decreased pyrene bioaccumulation from both contaminated soils. The presence of CNTs also affected pyrene elimination rates. After a 14-day exposure to pyrene-spiked soils, earthworms showed enhanced elimination rates in soils amended with 3.0 mg CNT/g but not 0.3 mg CNT/g. These results suggest that the presence of SWNTs or MWNTs in terrestrial ecosystems will have concentration-dependent effects on decreasing HOC accumulation by earthworms in a manner similar to that expected of most "hard" carbons.
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Affiliation(s)
- Elijah J Petersen
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
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Nanomaterials - acetylcholinesterase enzyme matrices for organophosphorus pesticides electrochemical sensors: a review. SENSORS 2009; 9:4034-55. [PMID: 22408512 PMCID: PMC3291897 DOI: 10.3390/s90604034] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 05/14/2009] [Accepted: 05/25/2009] [Indexed: 12/13/2022]
Abstract
Acetylcholinesterase (AChE) is an important cholinesterase enzyme present in the synaptic clefts of living organisms. It maintains the levels of the neurotransmitter acetylcholine by catalyzing the hydrolysis reaction of acetylcholine to thiocholine. This catalytic activity of AChE is drastically inhibited by trace amounts of organophosphorus (OP) pesticides present in the environment. As a result, effective monitoring of OP pesticides in the environment is very desirable and has been done successfully in recent years with the use of nanomaterial-based AChE sensors. In such sensors, the enzyme AChE has been immobilized onto nanomaterials like multiwalled carbon nanotubes, gold nanoparticles, zirconia nanoparticles, cadmium sulphide nano particles or quantum dots. These nanomaterial matrices promote significant enhancements of OP pesticide determinations, with the thiocholine oxidation occurring at much lower oxidation potentials. Moreover, nanomaterial-based AChE sensors with rapid response, increased operational and long storage stability are extremely well suited for OP pesticide determination over a wide concentration range. In this review, the unique advantages of using nanomaterials as AChE immobilization matrices are discussed. Further, detection limits, sensitivities and correlation coefficients obtained using various electroanalytical techniques have also been compared with chromatographic techniques.
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