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1.
Biosolids are the treated organic residuals, also known as sludge, that are generated from domestic wastewater treatment plants.
According to the USEPA, over 7 millions tons (dry weight) of biosolids are generated every year in the US by more than the
16,000 wastewater treatment plants and a large portion of these biosolids is disposed on land. Nuisance odors, the potential
of pathogen transmission, and presence of toxic and persistent organic chemicals and metals in biosolids have for the most
part limited the use of land applications. This paper presents zero-valent iron nanoparticles (1–100 nm) for the treatment
and stabilization of biosolids. Iron nanoparticles have been shown to form stable and nonvolatile surface complexes with malodorous
sulfur compounds such as hydrogen sulfide and methyl sulfides, degrade persistent organic pollutants such as PCBs and chlorinated
pesticides, and sequestrate toxic metal ions such as mercury and lead. The end products from the nanoparticle reactions are
iron oxides and oxyhydroxides, similar to the ubiquitous iron minerals in the environment. Due to the large surface area and
high surface reactivity, only a relatively low dose (<0.1% wt) of iron nanoparticles is needed for effective biosolids stabilization.
The iron nanoparticle technology may thus offer an economically and environmentally sustainable and unique solution to one
of the most vexing environmental problems. 相似文献
2.
In this study, the rectorite-supported nanoscale zero-valent iron (nZVI/R) was synthesized through a reduction method. X-ray diffraction analysis showed the existence of the nZVI in the nZVI/R composite and X-ray photoelectron spectroscopy analysis indicated that the nZVI particles were partly oxidized into iron oxide. Scanning electron microscopy analysis revealed that the nZVI particles were highly dispersed on the surface of the rectorite. The specific surface area of the nZVI/R composite is 21.43 m2/g, which was higher than that of rectorite (4.30 m2/g) and nZVI (17.97 m2/g). In the presence of ultrasound (US), the degradation of methyl orange and metronidazole by the nZVI/R composite was over 93% and 97% within 20 min, respectively, which is much higher than that by the rectorite and the nZVI. The degradation ratio of methyl orange and metronidazole by the nZVI/R composite under US was 1.7 and 1.8 times as high as that by the nZVI/R composite without US, respectively. The mechanism of the enhanced degradation of methyl orange and metronidazole under US irradiation was studied. These results indicate that the US/nZVI/R process has great potential application value for treatment of dye wastewater and medicine wastewater. 相似文献
3.
Zero valent iron nanoparticles are of increasing interest in clean water treatment applications due to their reactivity toward
organic contaminants and their potential to degrade a variety of compounds. This study focuses on the effect of organophosphate
stabilizers on nanoparticle characteristics, including particle size distribution and zeta potential, when the stabilizer
is present during nanoparticle synthesis. Particle size distributions from DLS were obtained as a function of stabilizer type
and iron precursor (FeSO4·7H2O or FeCl3), and nanoparticles from 2 to 200 nm were produced. Three different organophosphate stabilizer compounds were compared in
their ability to control nanoparticle size, and the size distributions obtained for particle volume demonstrated differences
caused by the three stabilizers. A range of stabilizer-to-iron (0.05–0.9) and borohydride-to-iron (0.5–8) molar ratios were
tested to determine the effect of concentration on nanoparticle size distribution and zeta potential. The combination of ferrous
sulfate and ATMP or DTPMP phosphonate stabilizer produced stabilized nanoparticle suspensions, and the stabilizers tested
resulted in varying particle size distributions. In general, higher stabilizer concentrations resulted in smaller nanoparticles,
and excess borohydride did not decrease nanoparticle size. Zeta potential measurements were largely consistent with particle
size distribution data and indicated the stability of the suspensions. Probe sonication, as a nanoparticle resuspension method,
was minimally successful in several different organic solvents. 相似文献
4.
This study investigated the degradation of propranolol (PRO), a beta (β)-blockers, by nano zero-valent iron (nZVI) activated persulfate (PS) under ultrasonic irradiation. Effects of several critical factors were evaluated, inclusive of PS concentration, nZVI dosage, ultrasound power, initial pH, common anions, and chelating agent on PRO degradation kinetics. Higher PS concentration, nZVI dosage and ultrasound power as well as acidic pH favored the PRO degradation. Conversely, anions and chelating agent took on the inhibitory effect towards PRO degradation to different extents. Furthermore, the variations of morphology and surface composition of nZVI before and after the reaction were characterized by TEM, XRD and XPS. Finally, on the basis of identified degradation intermediates by LC/MS/MS analysis, this work tentatively proposed the degradation pathways. These encouraging results suggest that US/nZVI/PS process is a promising strategy for the treatment of PRO-induced water pollutant. 相似文献
5.
Rüstem Keçili Ayça Atılır Özcan Arzu Ersöz Deniz Hür Adil Denizli Rıdvan Say 《Journal of nanoparticle research》2011,13(5):2073-2079
The nanoparticle comprises a superparamagnetic iron oxide nanoparticle core conjugated with trimethoxylsilyl propylmethacrylate
(TMSPM) and methacryloylamido serine (MASE), methacryloylamido histidine (MAH), methacryloylamido glutamic acid (MAGA) monomers,
and p-nitrophenyl palmitate (p-NPP) which is a substrate of lipase as a template molecule, which enables the creation of lipase active region. The resulting
hybrid superparamagnetic nanotraps are magnetically separable, highly active, and stable under harsh conditions. In this study,
the advantages of high selectivity of molecular imprinting technique have used to get mimic lipase for the synthesis of methyl
jasmonate and methyl oleate. 相似文献
6.
Ibrahim SharifiH. Shokrollahi S. Amiri 《Journal of magnetism and magnetic materials》2012,324(6):903-915
Magnetic ferrofluids (magnetic nanofluids) have received special attention due to their various biomedical applications such as drug delivery and hyperthermia treatment for cancer. The biological applications impose some special requirements. For example, the well-known iron oxide ferrofluids become undesirable because their iron atoms are poorly distinguishable from those of hemoglobin. A conceivable solution is to use mixed-ferrites (MFe2O4 where M=Co, Mn, Ni, Zn) to have a range of magnetic properties. These ferrites have attracted special attention because they save time, and because of their low inherent toxicity, ease of synthesis, physical and chemical stabilities and suitable magnetic properties. Based on the importance of ferrite particles in ferrofluids for hyperthermia treatment, this paper gives a summary on the physical concepts of ferrofluids, hyperthermia principal, magnetic properties and synthesis methods of nanosized ferrites. 相似文献
7.
《Current Applied Physics》2018,18(11):1410-1414
Magnetic nanoparticles (MNP) have attracted considerable interest in many fields of research and applied science due to their impressive properties. In the past, especially biomedical problems have promoted the development of MNPs. For technical applications e.g. wastewater treatment and absorption of electromagnetic waves, the existing synthesis approaches are too expensive and/or the producible quantities are too low. In this work we present a method for simple preparation of size-controlled magnetic iron oxide nanoparticles by electroerosion dispersion (EED) of carbon steel in water. We describe the synthesis method, the laboratory installation and discuss the structural, chemical and electromagnetic properties of the synthetized EED powders as well as their applicability for microwave absorption compared to other available ferrite powders. 相似文献
8.
Tatsuro Endo Hikaru TakizawaYasunori Imai Yasuko Yanagida Takeshi Hatsuzawa 《Applied Surface Science》2011,257(7):2560-2566
The specific optical characteristics which can be observed from noble metal nanostructured materials such as nanoparticles and nanoislands have wide variety of applications such as biosensors, solar cells, and optical circuit. Because, these noble metal nanostructures induce the increment of light absorption efficiency by the enhancing effect of electrical field from localized surface plasmon resonance (LSPR) excitation. However, the enhancing effects of electrical field from LSPR using simple structured noble metal nanostructures for several applications are not satisfactory. To realize the more effective light absorption efficiency by the enhancing effect of electrical field, quite different noble metal nanostructures have been desired for applying to several applications using LSPR. In this study, to obtain the more effective enhancing effect of electrical field, conditions for LSPR excitation using a gold-capped nanoparticle layer substrate are computationally analyzed using finite-difference time-domain (FDTD) method. From the previous research, LSPR excitation using such gold-capped nanoparticle layer substrates has a great potential for application to high-sensitive label-free monitoring of biomolecular interactions. For understanding of detailed LSPR excitation mechanism, LSPR excitation conditions were investigated by analyzing the electrical field distribution using simulation software and comparing the results obtained with experimental results. As a result of computational analysis, LSPR excitation was found to depend on the particle alignment, interparticle distance, and excitation wavelength. Furthermore, the LSPR optical characteristics obtained from the simulation analysis were consistent with experimentally approximated LSPR optical characteristics. Using this gold-capped nanoparticle layer substrate, LSPR can be excited easily more than conventional noble metal nanoparticle-based LSPR excitation without noble metal nanoparticle synthesis. Hence, this structure is detectable a small change of refractive index such as biomolecular interactions for biosensing applications. 相似文献
9.
Starowicz M Starowicz P Zukrowski J Przewo?nik J Lemański A Kapusta C Bana? J 《Journal of nanoparticle research》2011,13(12):7167-7176
We present a novel and facile method enabling synthesis of iron oxide nanoparticles, which are composed mainly of maghemite according to X-ray diffraction (XRD) and Mössbauer spectroscopy studies. The proposed process is realized by anodic iron polarization in deaerated LiCl solutions containing both water and ethanol. Water seems to play an important role in the synthesis. Morphology of the product was studied by means of transmission electron microscopy and XRD. In the solution containing almost 100% of water a black suspension of round shaped maghemite nanoparticles of 20–40 nm size is obtained. Regulating water concentration allows to control nanoparticle size, which is reduced to 4–6 nm for 5% of water with a possibility to reach intermediate sizes. For 3% or lower water concentration nanoparticles are of a needle-like shape and form a reddish suspension. In this case phase determination is problematic due to a small particle size with the thickness of roughly 3 nm. However, XRD studies indicate the presence of ferrihydrite. Coercivities of the materials are similar to those reported for nanoparticle magnetite powders, whereas the saturation magnetization values are considerably smaller. 相似文献
10.
Superparamagnetic iron oxide nanoparticles are used in diverse applications, including optical magnetic recording, catalysts,
gas sensors, targeted drug delivery, magnetic resonance imaging, and hyperthermic malignant cell therapy. Combustion synthesis
of nanoparticles has significant advantages, including improved nanoparticle property control and commercial production rate
capability with minimal post-processing. In the current study, superparamagnetic iron oxide nanoparticles were produced by
flame synthesis using a coflow flame. The effect of flame configuration (diffusion and inverse diffusion), flame temperature,
and additive loading on the final iron oxide nanoparticle morphology, elemental composition, and particle size were analyzed
by transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), energy dispersive spectroscopy (EDS), and Raman spectroscopy.
The synthesized nanoparticles were primarily composed of two well known forms of iron oxide, namely hematite αFe2O3 and magnetite Fe3O4. We found that the synthesized nanoparticles were smaller (6–12 nm) for an inverse diffusion flame as compared to a diffusion
flame configuration (50–60 nm) when CH4, O2, Ar, and N2 gas flow rates were kept constant. In order to investigate the effect of flame temperature, CH4, O2, Ar gas flow rates were kept constant, and N2 gas was added as a coolant to the system. TEM analysis of iron oxide nanoparticles synthesized using an inverse diffusion
flame configuration with N2 cooling demonstrated that particles no larger than 50–60 nm in diameter can be grown, indicating that nanoparticles did not
coalesce in the cooler flame. Raman spectroscopy showed that these nanoparticles were primarily magnetite, as opposed to the
primarily hematite nanoparticles produced in the hot flame configuration. In order to understand the effect of additive loading
on iron oxide nanoparticle morphology, an Ar stream carrying titanium-tetra-isopropoxide (TTIP) was flowed through the outer
annulus along with the CH4 in the inverse diffusion flame configuration. When particles were synthesized in the presence of the TTIP additive, larger
monodispersed individual particles (50–90 nm) were synthesized as observed by TEM. In this article, we show that iron oxide
nanoparticles of varied morphology, composition, and size can be synthesized and controlled by varying flame configuration,
flame temperature, and additive loading. 相似文献
11.
Non-uniform electric fields are utilized to direct the large scale assembly of colloidal nanoparticles in nanoscale structures
over large areas. Using micro- and nanoscale templates, various nanoparticles can be directly assembled into parallel wires,
cross-wires, and many other complex structures. The assembly process is controlled by electric field, time, and geometric
design of templates. The results show that single nanoparticle wires as small as 10 nm wide and 100,000 nm long as well as
other nanoparticle structures can be fabricated using electrophoresis over a large area. In addition, the directed assembly
of polymeric and conductive nanoparticle nanowires and networks has been demonstrated using dielectrophoresis. The nanoparticle
wires can be further oriented along the direction of an externally introduced hydrodynamic flow. The presented technique is
a promising approach for large scale manufacturing of nanoscale devices for many applications including biosensors and nanoelectronics. 相似文献
12.
Magnetite nanoparticle synthesis is becoming increasingly important in a variety of fields. Scale-up of current batch, laboratory magnetite precipitation techniques involving relatively small volumes may be problematic as large stirred vessels can yield areas of localized low pH upon addition of a base to an iron solution resulting in the precipitation of undesired non-magnetic iron oxides. We present the use of high-pressure impinging stream reactors of different designs for the potential large-scale continuous precipitation of magnetite nanoparticles. The experimental system described here is capable of producing up to 50 g/min predominantly magnetite precipitate of 8–12 nm particle diameter. 相似文献
13.
The ability to control the assembly of nanoparticle building blocks is critically important for the development of new materials
and devices. The properties and functions of nanomaterials are not only dependent on the size and properties of individual
particles, but also the interparticle distance and interactions. In order to control the structures of nanoassemblies, it
is important to first achieve a precise control on the chemical functionality of nanoparticle building blocks. This review
discusses three methods that have been reported recently for the preparation of monofunctional gold nanoparticles, i.e., nanoparticles
with a single chemical functional group attached to each particle. The advantages and disadvantages of the three methods are
discussed and compared. With a single functional group attached to the surface, one can treat such nanoparticles as molecular
building blocks to react with other molecules or nanoparticles. In other words, by using appropriate chemical reactions, nanoparticles
can be linked together into nanoassemblies and materials by covalent bonds, similar to the total chemical synthesis of complicated
organic compounds from smaller molecular units. An example of using this approach for the synthesis of nanoparticle/polymer
hybrid materials with optical limiting properties is presented. Other potential applications and advantages of covalent bond-based
nanoarchitectures vs. non-covalent interaction-based supramolecular self-assemblies are also discussed briefly in this review. 相似文献
14.
Nanoscale Iron Particles for Environmental Remediation: An Overview 总被引:40,自引:0,他引:40
Nanoscale iron particles represent a new generation of environmental remediation technologies that could provide cost-effective solutions to some of the most challenging environmental cleanup problems. Nanoscale iron particles have large surface areas and high surface reactivity. Equally important, they provide enormous flexibility for in situ applications. Research has shown that nanoscale iron particles are very effective for the transformation and detoxification of a wide variety of common environmental contaminants, such as chlorinated organic solvents, organochlorine pesticides, and PCBs. Modified iron nanoparticles, such as catalyzed and supported nanoparticles have been synthesized to further enhance the speed and efficiency of remediation. In this paper, recent developments in both laboratory and pilot studies are assessed, including: (1) synthesis of nanoscale iron particles (10–100nm, >99.5% Fe) from common precursors such as Fe(II) and Fe(III); (2) reactivity of the nanoparticles towards contaminants in soil and water over extended periods of time (e.g., weeks); (3) field tests validating the injection of nanoparticles into aquifer, and (4) in situ reactions of the nanoparticles in the subsurface. 相似文献
15.
16.
Ming-Liang Liao 《Journal of nanoparticle research》2012,14(4):1-13
We report a new chemical approach toward air-stable nanoscale zero-valent iron (nZVI). The uniformly sized (approx. 80?nm) particles, formed by the reduction of Fe(II) salt by borohydride in the presence of glutamic acid, are coated by a thin inner shell of amorphous ferric oxide/hydroxide and a secondary shell consisting of glutamic acid. The as-prepared nanoparticles stabilized by the inorganic?Corganic double shell create 2D chain morphologies. They are storable for several months under ambient atmosphere without the loss of Fe(0) relative content. They show one order of magnitude higher rate constant for trichlorethene decomposition compared with the pristine particles possessing only the inorganic shell as a protective layer. This is the first example of the inorganic?Corganic (consisting of low-molecular weight species) double-shell stabilized nanoscale zero-valent iron material being safely transportable in solid-state, storable on long-term basis under ambient conditions, environmentally acceptable for in situ applications, and extraordinarily reactive if contacted with reducible pollutants, all in one. 相似文献
17.
C. H. Lin L. Jiang Y. H. Chai H. Xiao S. J. Chen H. L. Tsai 《Applied Physics A: Materials Science & Processing》2010,98(4):855-860
This article demonstrates an efficient approach to fabricate nanoparticles arranged in a periodic pattern over a large area.
A nanoscale gold film coated on a silicon wafer substrate was sectioned into grids by focused ion beam machining. Through
a thermal treatment, the film in a confined area transforms into a nanoparticle due to the surface tension effect of the melted
gold film. By controlling the film thickness and the size of the confined area, a nanoparticle array with various particle
sizes and interparticle spacings can be manipulated. This approach may have great potential applications in sensor chips and
nonlinear devices. 相似文献
18.
Zinc Oxide is an important and multi-purpose material in various industries due to its particular chemical and physical properties. Discovering a cheap, fast, clean, safe, and easy to use method, to synthesize this oxide nanoparticle has attracted a lot of attention in recent applications. The unique properties of the microwave and its special heating capabilities have yielded desirable outcomes by combining different synthesis methods. In the recent years, the vast majority of studies focus on the microwave-assisted synthesis of zinc oxide nanoparticles. This review article attempts to go over the recent advancements on the synthesis of zinc oxide nanoparticles with the aid of microwave, different morphologies and applications obtained by this method. Various microwave-assisted synthesis methods are classified, including the solution-based methods such as hydrothermal, sol-gel, and combustion methods. Morphology of the nanoparticles can affect the properties, and subsequently, applications of these nanoparticles. On the other hand, there is great diversity of morphological and synthesis conditions of zinc oxide nanoparticles. Thus, categorizing the synthesis techniques and providing features of them, facilitates the selection of appropriate method for designing new hierarchical structures with potential properties for future applications. Also it is endeavored to focus on the formation mechanisms of these methods. Finally, the various morphologies obtained under microwave radiation and their formation mechanisms are discussed and the effective factors in the synthesis are analyzed and presented. The potential and suitable fields of development and progress in the future studies are also proposed. 相似文献
19.
《Journal of magnetism and magnetic materials》2005,293(1):75-79
Iron and cobalt nanoparticle fluids have been prepared by inert-gas condensation into an oil/surfactant mixture. Superparamagnetic iron fluids (mean particle size=11.6±0.4 nm) and ferromagnetic cobalt fluids (mean particle size=51.6±3.4 nm) produced by this technique are promising candidates for magnetic targeting and hyperthermia applications. 相似文献
20.
?i?dem ??hedef Serap Teks?z Perihan ünak Emin ?. Medine Türkan Ertay Recep Beki? 《Journal of nanoparticle research》2012,14(8):1-8
The degradation of crystal violet in aqueous solution was investigated using kaolin-supported zero-valent iron nanoparticles (K-nZVI). It was found that K-nZVI with a ratio of kaolin:zero-valent iron nanoparticles (nZVI) at 1:1 was most effective in removing crystal violet. Batch experiments show that more than 97.29?% crystal violet was degraded using K-nZVI, while only 24.36?% was removed using nZVI after reacting for 7?min, where the solution contained 100?mg?L?1 crystal violet at pH 6.5. This is due to a decrease in aggregation of Fe0 nanoparticles and enhanced their reactivity in the presence of kaolin, which was confirmed by the characterization using scanning electron microscopy. X-ray diffraction shows the formation of iron oxide and hydroxide, while UV?CVis spectral shows that the absorption peak of crystal violet was reduced, as well as Fourier transform infrared shows that new bands were formed after K-nZVI reacting with crystal violet. These suggest that degradation of crystal violet by K-nZVI include the oxidation of iron, the adsorption of crystal violet onto the K-nZVI, the transformation of crystal violet to leuko-crystal violet, and finally the cleavage of C=C bond. 相似文献