共查询到20条相似文献,搜索用时 31 毫秒
1.
Fang G Si Y Tian C Zhang G Zhou D 《Environmental science and pollution research international》2012,19(3):784-793
Purpose
Degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) in soils by Fe3O4 nanoparticles combined with soil indigenous microbes was investigated, and the effects of Fe3O4 nanoparticles on soil microbial populations and enzyme activities were also studied. 相似文献2.
Adsorption of Pb,Cd, Cu,Zn, and Ni to titanium dioxide nanoparticles: effect of particle size,solid concentration,and exhaustion 总被引:2,自引:1,他引:1
Karen E. Engates Heather J. Shipley 《Environmental science and pollution research international》2011,18(3):386-395
Purpose
Adsorption of metals (Pb, Cd, Cu, Ni, Zn) to TiO2 nanoparticles and bulk particles was examined for use as a contaminant removal substrate as a function of particle size, sorbent concentration, and exhaustion. 相似文献3.
Alqudami A Alhemiary NA Munassar S 《Environmental science and pollution research international》2011,19(7):2832-2841
Purpose
This work aimed at investigating the adsorption of lead and cadmium onto Fe and Ag nanoparticles for use as a water contaminant removal agent as a function of particle type, sorbent concentration, and contact time.Methods
Fe and Ag spherical nanoparticles were prepared in water by the lab-made electro-exploding wire (EEW) system and were investigated for their structure properties. Adsorption experiments were carried out at room temperature and pH 8.3 water solutions.Results
The removal/adsorption of both Pb(II) and Cd(II) ions was found to be dependent on adsorbent dosage and contact time. Pb(II) adsorption onto Fe and Ag nanoparticles showed more or less similar efficiency and behavior. The kinetic data for the adsorption process obeyed pseudo second-order rate equations. The calculated equilibrium adsorption capacities (q e) were 813 and 800 mg/g for Pb sorption onto Fe and Ag nanoparticles, respectively. Cd(II) ion adsorption onto Fe nanoparticles obeyed pseudo second-order rate equations with q e equal to 242 mg/g, while their adsorption onto Ag nanoparticles obeyed pseudo first-order rate equations with q e of 794 mg/g. The calculated q es are in quite agreement with the experimental values. The removal/uptake mechanisms of metal ions involved interaction between the metal ion and the oxide/hydroxyl layer around the spherical metallic core of the nanoparticle in water medium.Conclusion
Fe and Ag nanoparticles prepared using the EEW technique exhibited high potentials for the removal of metal ions from water with very high adsorption capacities, suggesting that the EEW technique can be enlarged to generate nanoparticles with large quantities for field or site water purification. 相似文献4.
Sorption of phenanthrene by nanosized alumina coated with sequentially extracted humic acids 总被引:1,自引:0,他引:1
Kun Yang Lizhong Zhu Baoshan Xing 《Environmental science and pollution research international》2010,17(2):410-419
Background, aim, and scope
Sorption of hydrophobic organic compounds (HOCs) to natural organic matter (NOM) is an important process that affects the transport, transformation, bioavailability, and fate of HOCs in the environment. Manufactured nanoparticles (NPs) such as nano-oxides will inevitably enter the environment in the processes of their production, transfer, and use and could be coated by the ubiquitous NOM. Thus, sorption of HOCs to NOM in the environment could be affected by the NP interactions with NOM. Furthermore, the toxicity of nano-oxides could be increased due to the adsorbed HOCs. Therefore, sorption of phenanthrene by nano-Al2O3 coated with humic acid (HA) was examined in this study to explore the possible effect of nanoparticles (NPs) on the environmental behavior of HOCs and the potential environmental and health risks of NPs. 相似文献5.
Introduction
Titanium dioxide (TiO2) nanoparticle powders have been extensively studied to quickly photodegrade some organic pollutants; however, the effect of the particle size of TiO2 nanoparticle aggregates on degradation remains unclear because microscale aggregates form once the nanoparticle powders enter into water.Methods
The degradation of azo dye by different particle sizes of TiO2 nanoparticle aggregates controlled by NaCl concentrations was investigated to evaluate the particle size effect. Removal reactions of reactive black 5 (RB5) with TiO2 nanoparticles followed pseudo-first-order kinetics.Results
The increase of TiO2 dosage from 40 to 70?mg/L enhanced the degradation. At doses around 100?mg/L TiO2, degradation rates decreased which could be the result of poor UV light transmittance at high-particle concentrations. At average particle sizes of TiO2 nanopowders less than around 500?nm, the degradation rates increased with decreasing particle size. As the average particle size exceeded 500?nm, the degradation rates were not significantly changed.Conclusions
For the complete degradation experiments, the mineralization rates of total organic carbon disappearance are generally following the RB5 decolorization kinetic trend. These findings can facilitate the application of TiO2 nanoparticles to the design of photodegradation treatments for wastewater. 相似文献6.
Men HF Liu HQ Zhang ZL Huang J Zhang J Zhai YY Li L 《Environmental science and pollution research international》2012,19(6):2271-2280
Introduction
Magnetic Fe3O4 nanoparticles were prepared by coprecipitation and then were coated with SiO2 on the surface.Materials and methods
Fe3O4@SiO2 composite microspheres were modified by KH570. Using molecular imprinting technology, atrazine magnetic molecularly imprinted polymer was prepared by using atrazine as template molecule, methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linkers. The morphology, composition and magnetic properties of magnetic nanoparticles were characterized. The recognition selectivity of polymer was studied for template molecule and simulation by UV spectrophotometry. The adsorption properties and selectivity ability were analyzed by Scatchard analysis.Results
Scatchard linear regression analysis indicated that there are two binding sites of the target molecules. The magnetic molecularly imprinted polymer has been applied to the analysis of atrazine in real samples.Conclusion
The results show that: the recovery rates and the relative standard deviation were 94.0??98.7% and 2.1??4.0% in corn, the recovery rates and the relative standard deviation were 88.7??93.5% and 2.8??7.2% in water. 相似文献7.
Svanfelt J Eriksson J Kronberg L 《Environmental science and pollution research international》2011,18(6):871-876
Purpose
The direct aqueous photolysis of the thyroid hormone levothyroxine (T4) has been studied. 相似文献8.
Effect of Pb toxicity on leaf growth, antioxidant enzyme activities, and photosynthesis in cuttings and seedlings of Jatropha curcas L 总被引:3,自引:0,他引:3
Shu X Yin L Zhang Q Wang W 《Environmental science and pollution research international》2012,19(3):893-902
Background
Cuttings and seedlings of Jatropha curcas L. were exposed to different regimes of lead (Pb) stress as Pb(NO3)2 at 0 (CK), 0.5, 1, 2, 3, and 4 mM kg−1 soil. 相似文献9.
Karin Wiench Wendel Wohlleben Volker Hisgen Kristin Radke Edward Salinas Sabine Zok Robert Landsiedel 《Chemosphere》2009,76(10):1356-1365
Among the emerging literature addressing the biological effects of nanoparticles, very little information exists, particularly on aquatic organisms, that evaluates nanoparticles in comparison to non-nanocounterparts. Therefore, the potential effects of nano-scale and non-nano-scale TiO2 and ZnO on the water flea, Daphnia magna, were examined in 48-h acute toxicity tests using three different test media, several pigment formulations – including coated nanoparticles – and a variety of preparation steps. In addition, a 21-d chronic Daphnia reproduction study was performed using coated TiO2 nanoparticles. Analytical ultracentrifugation analyses provided evidence that the nanoparticles were present in a wide range of differently sized aggregates in the tested dispersions. While no pronounced effects on D. magna were observed for nano-scale and non-nano-scale TiO2 pigments in 19 of 25 acute (48-h) toxicity tests (EC50 > 100 mg L−1), six acute tests with both nano- and non-nano-scale TiO2 pigments showed slight effects (EC10, 0.5–91.2 mg L−1). For the nano-scale and non-nano-scale ZnO pigments, the acute 48-h EC50 values were close to the 1 mg L−1 level, which is within the reported range of zinc toxicity to Daphnia. In general, the toxicity in the acute tests was independent of particle size (non-nano-scale or nano-scale), coating of particles, aggregation of particles, the type of medium or the applied pre-treatment of the test dispersions. The chronic Daphnia test with coated TiO2 nanoparticles demonstrated that reproduction was a more sensitive endpoint than adult mortality. After 21 d, the NOEC for adult mortality was 30 mg L−1 and the NOEC for offspring production was 3 mg L−1. The 21-d EC10 and EC50 values for reproductive effects were 5 and 26.6 mg L−1, respectively. This study demonstrates the utility of evaluating nanoparticle effects relative to non-nano-scale counterparts and presents the first report of chronic exposure to TiO2 nanoparticles in D. magna. 相似文献
10.
?árka Pau?ová Josef Krysa Jaromír Jirkovsky Gilles Mailhot Vanessa Prevot 《Environmental science and pollution research international》2012,19(9):3709-3718
Introduction
Efficient immobilization of TiO2 nanoparticles on the surface of Mg2Al-LDH nanosheets was performed by delamination/restacking process.Experimental part
The structural and textural properties of as-prepared nanocomposite were deeply analyzed using different solid-state characterization techniques such as: X-ray powder diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopies, chemical analysis, X-ray photoelecton spectroscopy, N2 adsorption?Cdesorption, and electronic microscopy.Results and discussion
The photocatalytic properties of immobilized TiO2 nanoparticles on Mg2Al were investigated using the photodegradation of two model pollutants: Orange II and 4-chlorophenol, and compared with pure colloidal TiO2 solution.Conclusion
It appears that Orange II photodegradation was systematically faster and more efficient than 4-chlorophenol photodegradation regardless of the medium pH. Moreover under slightly basic conditions, even if the TiO2 photocatalytic efficiency decreases, photodegradation performed in presence of easily recovered TiO2/Mg2Al1.5 nanocomposite gives rise to comparable or better results than pure TiO2. 相似文献11.
Manzo S Rocco A Carotenuto R Picione Fde L Miglietta ML Rametta G Di Francia G 《Environmental science and pollution research international》2011,18(5):756-763
Introduction
Nanomaterials have widespread applications in several industrial sectors. ZnO nanoparticles (NPs) are among the most commonly used metal oxide NPs in personal care products, coating and paints. However, their potential toxicological impact on the environment is largely unexplored. 相似文献12.
Hairong Cheng Hai Guo Xinming Wang Sam M. Saunders S. H. M. Lam Fei Jiang Tijian Wang Aijun Ding Shuncheng Lee K. F. Ho 《Environmental science and pollution research international》2010,17(3):547-560
Background, aim, and scope
Photochemical smog, characterized by high concentrations of O3 and fine particles, is of great concern in the urban areas, in particular megacities and city clusters like the Pearl River Delta. 相似文献13.
Li P Wang X Allinson G Li X Stagnitti F Murray F Xiong X 《Environmental science and pollution research international》2011,18(7):1090-1097
Background
Open-top chambers were used to study the impact of simultaneous exposure to atmospheric SO2 pollution and heavy metal contamination in soils on the metal contents and productivity of soybean plant. 相似文献14.
Eduardo Yubero Adoración Carratalá Javier Crespo Jose Nicolás Milagros Santacatalina Silvia Nava Franco Lucarelli Massimo Chiari 《Environmental science and pollution research international》2011,18(1):64-74
Introduction
The concentrations of trace metals, ionic species, and carbonaceous components in PM10 (particulate matter with aerodynamic diameters smaller than 10 μm) were measured from samples collected near an industrial complex, primarily composed of cement plants, in southeastern Spain, from September 2005 to August 2006. 相似文献15.
《Atmospheric environment (Oxford, England : 1994)》2001,35(20):3405-3412
Personal exposures, residential indoor, outdoor and workplace levels of nitrogen dioxide (NO2) were measured for 262 urban adult (25–55 years) participants in three EXPOLIS centres (Basel; Switzerland, Helsinki; Finland, and Prague; Czech Republic) using passive samplers for 48-h sampling periods during 1996–1997. The average residential outdoor and indoor NO2 levels were lowest in Helsinki (24±12 and 18±11 μg m−3, respectively), highest in Prague (61±20 and 43±23 μg m−3), with Basel in between (36±13 and 27±13 μg m−3). Average workplace NO2 levels, however, were highest in Basel (36±24 μg m−3), lowest in Helsinki (27±15 μg m−3), with Prague in between (30±18 μg m−3). A time-weighted microenvironmental exposure model explained 74% of the personal NO2 exposure variation in all centres and in average 88% of the exposures. Log-linear regression models, using residential outdoor measurements (fixed site monitoring) combined with residential and work characteristics (i.e. work location, using gas appliances and keeping windows open), explained 48% (37%) of the personal NO2 exposure variation. Regression models based on ambient fixed site concentrations alone explained only 11–19% of personal NO2 exposure variation. Thus, ambient fixed site monitoring alone was a poor predictor for personal NO2 exposure variation, but adding personal questionnaire information can significantly improve the predicting power. 相似文献
16.
Background
In this study, manganese dioxide-coated multiwall carbon nanotube (MnO2/CNT) nanocomposite has been successfully synthesized. 相似文献17.
Heather J. Shipley Sujin Yean Amy T. Kan Mason B. Tomson 《Environmental science and pollution research international》2010,17(5):1053-1062
Introduction
Arsenic is a well known water contaminant that causes toxicological and carcinogenic effects. In this work magnetite nanoparticles were examined as possible arsenic sorbents. The objective of this work was to develop a sorption kinetics model, which could be used to predict the amount of arsenic adsorbed by magnetite nanoparticles in the presence of naturally occurring species using a first-order rate equation, modified to include adsorption, described by a Langmuir isotherm. 相似文献18.
Joris J. H. Haftka Harrie A. J. Govers John R. Parsons 《Environmental science and pollution research international》2010,17(5):1070-1079
Background, aim, and scope
The behavior of polycyclic aromatic hydrocarbons (PAHs) is affected by dissolved organic matter (DOM) present in pore water of soils and sediments. Since partitioning to DOM reduces the bioavailable or freely dissolved PAH concentration in pore water, it is important to assess the effect of environmental variables on the magnitude of dissolved organic matter to water partition coefficients (K DOC). The objective of this study was to apply passive samplers to measure freely dissolved PAHs allowing depletion from the aqueous phase. The method was applied to determine K DOC at different temperatures for a selection of PAHs with natural DOM of very different origin. 相似文献19.
Wavelet transform-based artificial neural networks (WT-ANN) in PM10 pollution level estimation, based on circular variables 总被引:1,自引:0,他引:1
Shekarrizfard M Karimi-Jashni A Hadad K 《Environmental science and pollution research international》2012,19(1):256-268
Introduction
In this paper, a novel method in the estimation and prediction of PM10 is introduced using wavelet transform-based artificial neural networks (WT-ANN). 相似文献20.
Tang T Hurraß J Gminski R Mersch-Sundermann V 《Environmental science and pollution research international》2012,19(9):3840-3849