Final Report: Transformation of Halogenated PBTs with Nanoscale Bimetallic Particles

EPA Grant Number: GR832225
Alternative EPA Grant Number: R832225
Title: Transformation of Halogenated PBTs with Nanoscale Bimetallic Particles
Investigators: Zhang, Wei-xian
Institution: Lehigh University
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 2005 through December 31, 2007 (Extended to December 31, 2008)
Project Amount: $325,000
RFA: Exploratory Research to Anticipate Future Environmental Issues: Impacts of Manufactured Nanomaterials on Human Health and the Environment (2003) RFA Text |  Recipients Lists
Research Category: Nanotechnology , Health Effects , Hazardous Waste/Remediation , Health , Safer Chemicals

Objective:

The goal of this research is to develop nanoscale bimetallic particles (e.g., Fe-Pd, Fe-Ni, Fe-Ag) with sizes in the range of 1-100 nm for treatment of hydrophobic, persistent, bioaccumulative toxic compounds (PBTs) such as polychlorinated biphenyls (PCBs), DDT and lindane.

Specific objectives for this research include:  (1) development of novel synthetic methods to produce nanoparticles with targeted sizes, enhanced reactivity, and subsurface transport characteristics; (2) evaluation of the iron nanoparticles for PBT transformation; (3) assessment of the injection, transport, reaction, and long-term performance characteristics of iron nanoparticles in porous media; and (4) microscopic analyses of soil-nanoparticle-PBT interactions.

Summary/Accomplishments (Outputs/Outcomes):

Zero-valent iron nanoparticle technology is becoming a popular option for treatment of a variety of hazardous and toxic wastes, and for remediation of contaminated sites. As a matter of fact, nano iron has quickly become the most widely used nanomaterial in environmental remediation. In this research, we have to a great extent extended the applications of nano iron for the degradation of persistent organic pollutants (POPs). The synthesized nanoparticles have been assessed for their rate and extent of POP transformation. Model compounds studied in this research included PCBs, hexachlorocyclohexanes (HCHs), chlorinated benzenes, and phenols. Treatment of other common pollutants including arsenic and hexavalent chromium also was investigated. Significant progress has been made in: (1) synthesis and characterization of supported and unsupported nanoscale iron particles, (2) laboratory evaluation of the nanoparticles for the transformation of soil and groundwater contaminants, and (3) field demonstration of the nanoscale iron particles for in situ remediation.
 
1. Background
Nanomaterials refer collectively to engineered or natural materials with at least one characteristic dimension (e.g., length, diameter, thickness, or pore size) in the range of 1-100 nm. At this minute scale, nanomaterials exhibit distinct chemical, photochemical, mechanical, magnetic, and optical properties, which have led to their burgeoning applications in a diverse range of industries.
 
In the past decade, engineered nanomaterials have found increasing applications in environmental treatment and clean-up efforts. For example, nanomaterials with unique sorptive and reactive properties have been used in water and air purification, hazardous waste treatment, and in-situ site remediation. Among these, nanoscale iron (nano-iron) is the most widely used reactive agent. Various forms of nano-iron, including bimetallic nanoparticles and emulsified nano-iron, are applied in more than 90% of the field applications using nanomaterials according to a recent survey. Nanoscale calcium peroxide developed at Lehigh University represents another promising nanomaterial showing rapid increase in use for sites contaminated by hydrocarbon release from underground storage tanks (UST). With an estimated global market of approximately $10 million this year, environmental remediation with nanomaterials (dubbed as Nanoremediation here) is anticipated to grow rapidly and take up a significant share in the environmental clean-up market in the near future.
 
This report introduces the general properties of nanomaterials pertinent to environmental applications, followed by a more detailed account of major research accomplishments of STAR Grant GR832225.
 
2. Nanomaterials for Environmental Remediation – Competitive Advantages
The exceptional efficiency of nanomaterials in degrading and sequestrating environmental pollutants is attributed to the enormous reactive surfaces possessed by the nanoparticles and their ability to remain suspended in water for extended periods of time allowing extended contact with contaminants and facile transport through soil or groundwater media.
 
2.1 Surface area. As particle size decreases, the ratio of surface to bulk atoms increases. As surface atoms are involved in most physical and chemical processes, reduction in size generates more active sites to interface with, adsorb and react with contaminant molecules in the environmental media such as air, water and soil. For hydrophobic organic pollutants, the rate of surface-mediated transformations, e.g., oxidation of petroleum hydrocarbons, or reduction of chlorinated organic solvents, is a function of the reactive surface area:
                            (1)
Where kSA is the surface-area-normalized reaction rate constant.
Reactive surface area is estimated from the product of the dose of the agent and its specific surface area (SSA). For spherical particles with a diameter of d, the specific surface area (m2/kg) can be calculated by the following equation:
                                                               (2)
Where r is the density (kg/m3) of the solid particles. Commercial iron powders used in permeable reactive barriers (PRBs) have diameters typically on the order of 0.5 mm and thus a theoretical SSA of approximately 1.5 m2/kg. For nanoscale iron particles with an average diameter of 50 nm, the corresponding SSA is 15,000 m2/kg. Assuming other conditions are identical, nanoremediation requires much smaller amounts of materials to achieve the same remediation efficiency. The effects of size on surface area and material requirement are illustrated in Figure 1 below.
 
Figure 1: An illustration of the size effect on particle surface area.

2.2 Mobility. Soil and aquifer media impose a filtration effect on groundwater passing through them, which impede the mobility of solid particles carried along by the water. Suspended particles in water are subject to various forces, namely, gravitational, electrostatic, magnetic, and random Brownian motion. For large particles (>> 1 µm), gravity force predominates, resulting in rapid sedimentation and limited transverse mobility. On the other hand, the movement of nano-scale particles is largely governed by random Brownian motion. Constant collisions with water molecules cause arbitrary motion of very fine nanoparticles in water. Attractive electrostatic and magnetic forces (as in the case of iron) are the two main causes contributing to nanoparticle aggregation. Aggregation can be effectively mitigated by controlling the solution pH, ionic strength, and particle size and through the use of stabilizing agents. Laboratory studies have shown that iron nanoparticles stabilized by adding a small amount of naturally occurring polymers during synthesis processes can remain in suspension for extended periods of time (> 6 months) and migrate efficiently through sand-packed columns. The relatively high ionic strength typically found in groundwater also acts to suppress surface electrostatic charges and aids in stable dispersion of the nanoparticles.

2.3 Enhanced reactivity. The distinct physical, chemical and biological properties of nanomaterials, the most famous examples being carbon nanotubes and fullerene molecule (bucky ball, or C60), have been widely publicized thanks to popular science literature. In particular, the drastic change in chemical reactivity below a critical dimension has stimulated extensive research to exploit nanomaterials as catalytic agents. Gold, for example, is an inert material in the bulk state. However, nanoparticles of gold (<10 nm) have been demonstrated to be highly reactive, capable of catalyzing reactions such as oxidation of carbon monoxide and simple hydrocarbon molecules. High reactivity has been attributed to the presence of edge or corner atoms with partially fulfilled bonding environment, and the formation of active nano-clusters on substrate surfaces. In the case of nano-iron, the enhanced reactivity stems not only from its increased surface area and reactive sites, but also from its unique core-shell composite structure. Compared to bulk-scale iron materials, the oxide layer on nano-iron is highly disordered and it generally spans less than 10 nm in thickness. Because of these attributes, the oxide layer exhibits semiconductor-like behaviors, facilitating electron and charge transport between the aqueous phase and the interior metallic iron. Reactivity of nano-iron is further boosted by impregnating the nanoparticles with a tiny amount of a second metal, such as Pd, Ni, Ag, and Cu. The bimetallic nanoparticles (BNP) exhibit superior catalytic reactivity towards many halogenated compounds, including TCE, PCE, and PCBs, and are able to completely degrade these contaminants with little accumulation of undesirable intermediates.
 
2.4 Costs. A factor used to hinder large-scale deployment of nanomaterials for remediation is the perceived high cost of nanomaterials. During the early phase (prior to 2000) of our study of nano-iron at Lehigh University, there was no commercial supply of iron nanoparticles on the market. Synthesizing a few pounds of nano-iron for bench and pilot-scale tests was a tedious laboratory chore taking up days of labor if not longer. Not surprisingly, the cost was prohibitively high (>$200/lb). Tremendous progress in making nanoparticles affordable has been made since then. With the recent advent of mass production techniques such as high-speed precision ball-milling, the prices of nano-iron and nano-calcium peroxide have come down to the level of commodity chemicals. The ability to directly inject these nanoparticles by gravity or pressure feed to subsurface contaminant plumes allows additional cost savings compared to ex-situ treatment options and large-scale in-situ installations such as permeable reactive barriers (PRBs). The fact that nanoparticles are more reactive on a mass basis and the dosage required is typically a small fraction of that of the bulk remediation agent (see Figure 1) further contributes to their competitive edge over conventional materials in terms of performance per unit cost. Table 1 compares the costs of using nano-iron vs. other materials.
 
Table 1: Cost comparison based on reactive surface area
 
 1 mm
~10 µm
50 nm
Price (dollars/kg)
3.5
22
50
Surface area (m2/kg)
0.77
76.92
30,000
Unit cost (m2/dollar)
0.22
3.50
600
 
 
3. Major Research Accomplishments
 
3.1 Green manufacturing of nanoscale zero-valent iron (nZVI).  Despite its effectiveness in degrading a wide array of environmental contaminants and superior physical characteristics for subsurface delivery, large-scale applications of nanoscale zero-valent iron (nZVI) for environmental remediation have been inhibited by the high costs associated with its conventional production technologies. In this research, an environmentally benign and cost-effective production method of nZVI is demonstrated using a precision milling system. Unlike conventional methods such as chemical synthesis and vapor phase condensation, which typically involve toxic chemicals, sophisticated equipment and extensive labor, the precision milling method relies solely on the mechanical impact forces generated by stainless steel beads in a high-speed rotary chamber to break down the micro iron particles. The system uses no toxic solvents, is completely scalable to large-scale manufacturing. Scanning electron microscope (SEM) and BET surface area analysis independently verify that, after 8 hours of milling, the feed micro iron was effectively reduced to particles with sizes below 50 nm. The surface chemistry and crystal composition of the milled iron were characterized with high-resolution X-ray photoelectron spectroscopy (HR-XPS) and X-ray diffraction (XRD). Reactivity of the milled nZVI was probed through reactions with water and seven model chlorinated aliphatic compounds. The results demonstrate the milled nZVI (8 hour) is more reactive for contaminant degradation than the nZVI synthesized by the widely adopted borohydride reduction method. The precision milling method thus stands as a promising green process for large-scale nZVI production and enhances the prospect of the nZVI technology for large-scale environmental remediation.
 
Details have been published in:
Li SL, Yan WL, Zhang WX. Green production of nanoscale zero-valent iron (nZVI) with precision milling. Green Chemistry 2009;11:1618-1626.
 
3.2 Renewable hydrogen generation by zero valent iron nanoparticles. In this work, nanoscale zero valent iron (nZVI) is investigated for its potential for hydrogen generation. Laboratory experiments show that the iron-normalized hydrogen production rates vary from 15.2 to 58.3 mg-H2 kg-1-Fe hr-1 for nZVI, which are approximately two orders of magnitude higher than those of micro-sized iron particles. By doping with a 1% (w/w) noble metal such as Pd, Ni, Cu, or Ag on nZVI, the hydrogen generation rate can be accelerated by 2 to 39 times, with the highest hydrogen production rate of 1,490 mg-H2 kg-1-Fe hr-1 attained by Pd/Fe bimetallic nanoparticles. The system utilized here operates under ambient temperature and pressure and the hydrogen production rate is stable over time, which renders it easy to scale-up for large-scale production. The volumetric density of hydrogen storage in nZVI is estimated at 279 Kg H2 m-3, much higher than conventional hydrogen storage materials. Furthermore, spent iron nanoparticles can be regenerated by renewable carbon materials including waste biomass to make the overall production scheme environmentally and economically sustainable.
 
Details on this research have been submitted to the journal Green Chemistry for publication.
 
3.3 Preparation of mobile ZVI nanoparticles.  A method for the synthesis of fully dispersed and reactive nanoscale particles of ZVI has been developed. In this work, polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A), a nontoxic and biodegradable surfactant, is utilized to disperse the nanoscale nZVI. The addition of PV3A affected three key surface-related changes, which led to significant enhancements in particle stability and subsurface mobility potential. These included:  (1) a reduction of the mean nZVI particle size from 105 nm to 15 nm; (2) a reduction of the zeta (z) potential from +20 mV to -80 mV at neutral pH; and (3) a shift of the IEP from pH @ 8.1 to 4.5. XPS confirmed the sorption of PV3A on the nanoparticle surface and also the existence of ZVI (Fe0) in the nZVI mass. The appreciably smaller mean particle sizes and ability to remain in suspension should translate into greatly improved subsurface mobility potential.
 
Results of this work will be in:
Sun YP, Li XQ, Zhang WX. A method for the preparation of stable dispersion of zero-valent iron nanoparticles. Colloids and Surfaces A 2007;308:60-66.
 
3.4 Characterization of ZVI nanoparticles. In this research, a systematic characterization of the iron nanoparticles prepared with the method of ferric iron reduction by sodium borohydride was performed. This work confirms the core-shell structure of the ZVI nanoparticles. Particle size, size distribution, and surface composition were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), high resolution X-ray photoelectron spectroscopy (HR-XPS), X-ray absorption near edge structure (XANES), and acoustic/electroacoustic spectrometry. BET surface area, zeta (z) potential, isoelectric point (IEP), and solution Eh and pH also were measured. Methods and results obtained from this work may foster better understanding, facilitate information exchange, and contribute to further research and development of iron nanoparticles for environmental and other applications.
 
Details can be found in:
Sun Y-P, Li X-q, Cao J, Zhang W-x, Wang HP. Characterization of zero-valent iron nanoparticles. Advances in Colloid and Interface Science 2006;120(1-3):47-56.
 
3.5 Degradation of lindane by zero-valent iron nanoparticles.  In this research, laboratory synthesized particles of nanoscale iron were explored to degrade lindane, also known as gamma-hexachlorocyclohexane, a formerly widely utilized pesticide and well-documented persistent organic pollutant. In general, lindane disappeared from aqueous solution within 24 h in the presence of nanoiron concentrations ranging from 0.015 to 0.39 g/L. By comparison, approximately 40% of the initial lindane dose remained in solution after 24 h in the presence of 0.53 g/L of larger microscale iron particles. However, the surface area normalized first-order rate constants were all within the same order of magnitude regardless of dose or iron type. A key reaction intermediate, gamma-3,4,5,6-tetrachlorocyclohexene from dihaloelimination of lindane was identified and quantified. Trace levels of additional degradation products including benzene and biphenyl were detected but only in the high concentration experiments conducted in 50% ethanol. While up to 80% of the chlorine from the lindane molecules ended as chloride in water, only 38% of the expected chloride concentration was observed for the microscale iron experiment. This work together with previous published studies on the degradation of polychlorinated biphenyl, chlorinated benzenes, and phenols suggest that zero-valent iron nanoparticles can be effective in the treatment of more structurally complex and environmentally persistent organic pollutants such as lindane.
 
Major results of this work have appeared in:
Elliott DW, Lien HL, Zhang WX. Transformation of lindane with iron nanoparticles: mechanisms and kinetics. Journal of Environmental Engineering-ASCE 2009;135(5):317-324.
 
3.6 Application of ZVI nanoparticles for treatment of hexachlorocyclohexanes (HCHs).  In this work, groundwater and aquifer samples from a site contaminated by hexachlorocyclohexanes (HCHs, C6H6Cl6) were exposed to nanoscale iron particles to evaluate the technology as a potential remediation method. The total HCH burden in site groundwater was approximately 1,500 μg/L. In general, batch experiments with 2.2–27.0 g/L iron nanoparticles showed that more than 95% of the HCHs were removed from solution within 48 hours. The reactivity trend γ  α > β > δ was observed in terms of the rate of disappearance from solution. This trend appears to be correlated with the orientation (axial vs. equatorial) of the chlorine atoms lost in the dihaloelimination steps. Rate constants normalized to the iron surface area concentration, kN1, ranged from 5.4x10-4 to 8.8x10-4 L/m2-hr. The observed pseudo first-order rate constants (kobs) were in the range of 0.04–0.65 hr-1, comparable to previously determined values for lindane (γ-HCH). Post-test extractions of the reactor contents detected little HCH remaining in solution or on the solid surfaces, reinforcing the contention that reaction rather than sorption was the operative mechanism for the HCH removal. This work demonstrates the potential of nZVI nanoparticles for PBT treatment, which is the focus of this U.S. Environmental Protection Agency (EPA) Science To Achieve Results (STAR) project.
 
Partial results have been included in:
Elliott DW, Lien HL, Zhang WX. Zero-valent iron nanoparticles for treatment of groundwater contaminated by hexachlorocyclohexanes (HCHs). Journal of Environmental Quality 2008;37:2192-2201.
 
3.7 Encapsulation of arsenic by zero-valent iron nanoparticles.  Increasing evidence suggests that nanoscale zerovalent iron (nZVI) is effective for the removal of arsenic from contaminated water, but the immobilization mechanism is unclear. In particular, the existence of As(0) on the nanoparticle surface has been proposed but not substantiated in prior studies. By using high-resolution X-ray photoelectron spectroscopy (HR-XPS), we report clear evidence of As(0) species on nZVI surfaces after reactions with As(III) of As(V) species in solutions. These results prove that reduction to elemental arsenic by nZVI is an important mechanism for arsenic immobilization. Furthermore. reactions of nZVI with As(III) generated As(0), As(III), and As(V) on nanoparticle surfaces, indicating both reduction and oxidation of As(III) take place with nZVI treatment. The dual redox functions exhibited by nZVI are enabled by its, core-shell structure containing a metallic core with a highly reducing characteristic and a thin amorphous iron (oxy)hydroxide layer promoting As(III) coordination and oxidation. Results demonstrated here shed light on the underlying mechanisms of arsenic reactions with nZVI and suggest nZVI as a potential multifaceted agent for arsenic remediation.
 
More details of this investigation can be found in:
Ramos MAV, Yan W, Li XQ, Koel BE, Zhang WX. Simultaneous oxidation and reduction of arsenic by zero-valent iron nanoparticles: understanding the significance of the core-shell structure. Journal of Physical Chemistry C 2009;113(33):14591-14594.
 
3.8 Stabilization of biosolids with nanoscale nZVI.  Biosolids are the treated organic residuals, also known as sludge, that are generated from domestic wastewater treatment plants. According to the EPA, more than 7 million tons (dry weight) of biosolids are generated every year in the United States by the more than 16,000 wastewater treatment plants, and a large portion of these biosolids is disposed of on land. Nuisance odors, potential pathogen transmission, and the presence of toxic and persistent chemicals and metals in biosolids have, for the most part, limited the use of land applications.
 
We have tested ZVI nanoparticles 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. 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 thus may offer an economically and environmentally sustainable and unique solution to one of the most vexing environmental problems.
 
This work has been recently published:
Li X-Q, Brown DG, Zhang W-X. Stabilization of biosolids with nanoscale zero-valent iron (nZVI). Journal of Nanoparticle Research 2007;9(2):233-243.
 
3.9 nZVI—the core-shell structure and unique properties for Ni(II) sequestration.  More recent research suggests that iron nanoparticles function as a sorbent and a reductant for the sequestration of Ni(II) in water. A relatively high capacity of nickel removal is observed (0.13 g Ni/g Fe, or 4.43 meq Ni(II)/g), which is more than 100% higher than the best inorganic sorbents available. HR-XPS confirms that the ZVI nanoparticles have a core-shell structure and exhibit characteristics of both hydrous iron oxides (i.e., as a sorbent) and metallic iron (i.e., as a reductant). Ni(II) quickly forms a surface complex and then is reduced to metallic nickel on the nanoparticle surface. The dual properties of iron nanoparticles may offer efficient and unique solutions for the separation and transformation of metal ions and other environmental contaminants.
 
This work has been recently published in:
Li X-Q, Zhang W-X. Iron nanoparticles:  the core-shell structure and unique properties for Ni(II) sequestration. Langmuir 2006;22(10):4638-4642.
 
3.10 Sequestration of metal cations with ZVI nanoparticles—a study with HR-XPS.  In this work, applications of nZVI for removal of metal cations in water are investigated with the result that nZVI has much larger capacity than conventional materials for the sequestration of Zn(II), Cd(II), Pb(II), Ni(II), Cu(II), and Ag(I). Characterizations with HR-XPS confirm that the iron nanoparticles have a core-shell structure, which leads to exceptional properties for concurrent sorption and reductive precipitation of metal ions. For metal ions such as Zn(II) and Cd(II) with standard potential E0 very close to or more negative than that of iron (-0.41 V), the removal mechanism is sorption/surface complex formation. For metals with E0 greatly more positive than iron, for instance Cu(II), Ag(I), and Hg(II), the removal mechanism is predominantly reduction. Metals with E0 slightly more positive than iron, for example Ni(II) and Pb(II), can be immobilized at the nanoparticle surface by both sorption and reduction. The dual sorption and reduction mechanisms on top of the large surface of nanosized particles produce rapid reaction and high removal efficiency, and offer nZVI as a highly efficient material for treatment and immobilization of toxic heavy metals.
 
This work has appeared in:
Li X-Q, Zhang W-X. Sequestration of metal cations with zerovalent iron nanoparticles:  a study with high resolution X-ray photoelectron spectroscopy. Journal of Physical Chemistry C 2007;111(19):6939-6946.

Conclusions:

Results from this project have been widely disseminated, including more than 30 peer-reviewed papers and 40 invited presentations and seminars. Key aspects of this research are summarized in this final report.


Journal Articles on this Report : 28 Displayed | Download in RIS Format

Other project views: All 68 publications 28 publications in selected types All 28 journal articles
Type Citation Project Document Sources
Journal Article Cao J, Clasen P, Zhang W-X. Nanoporous zero-valent iron. Journal of Materials Research 2005;20(12):3238-3243. GR832225 (2005)
GR832225 (2006)
GR832225 (Final)
R829625 (Final)
  • Abstract: Journal of Materials Research-Abstract
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  • Journal Article Cao J, Elliott D, Zhang W-X. Perchlorate reduction by nanoscale iron particles. Journal of Nanoparticle Research 2005;7(4-5):499-506. GR832225 (2005)
    GR832225 (2006)
    GR832225 (Final)
    R829625 (2003)
    R829625 (Final)
  • Full-text: CMS-Full Text PDF
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  • Abstract: Springer-Abstract
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  • Journal Article Cao J, Zhang W-X. Stabilization of chromium ore processing residue (COPR) with nanoscale iron particles. Journal of Hazardous Materials 2006;132(2-3):213-219. GR832225 (2005)
    GR832225 (2006)
    GR832225 (Final)
    R829625 (Final)
  • Abstract from PubMed
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  • Abstract: ScienceDirect-Abstract
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  • Journal Article Cao J, Zhang W-X, Brown DG, Sethi D. Oxidation of lindane with Fe(II)-activated sodium persulfate. Environmental Engineering Science 2008;25(2):221-228. GR832225 (Final)
  • Abstract: Liebert-Abstract
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  • Journal Article Cao J, Li X, Tavakoli J, Zhang W-X. Temperature programmed reduction for measurement of oxygen content in nanoscale zero-valent iron. Environmental Science & Technology 2008;42(10):3780-3785. GR832225 (Final)
  • Abstract from PubMed
  • Abstract: ES&T-Abstract
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  • Journal Article Cheng R, Wang J-L, Zhang W-X. Comparison of reductive dechlorination of p-chlorophenol using Fe0 and nanosized Fe0. Journal of Hazardous Materials 2007;144(1-2):334-339. GR832225 (Final)
  • Abstract from PubMed
  • Full-text: ScienceDirect-Full Text HTML
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  • Abstract: ScienceDirect-Abstract
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  • Journal Article Elliott DW, Lien H-L, Zhang W-X. Zerovalent iron nanoparticles for treatment of ground water contaminated by hexachlorocyclohexanes. Journal of Environmental Quality 2008;37(6):2192-2201. GR832225 (Final)
  • Abstract from PubMed
  • Full-text: National University of Kaohsiung-Full Text PDF
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  • Abstract: JEQ-Abstract
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  • Journal Article Elliott DW, Lien H-L, Zhang W-X. Degradation of lindane by zero-valent iron nanoparticles. Journal of Environmental Engineering-ASCE 2009;135(5):317-324. GR832225 (Final)
  • Full-text: National University of Kaohsiung-Full Text PDF
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  • Abstract: ASCE-Abstract
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  • Journal Article Li S, Elliott DW, Spear ST, Ma LM, Zhang W-X. Hexachlorocyclohexanes in the environment: mechanisms of dechlorination. Critical Reviews in Environmental Science and Technology 2011;41(19):1747-1792. GR832225 (Final)
  • Abstract: Taylor&Francis-Abstract
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  • Journal Article Li S, Yan W, Zhang W-X. Solvent-free production of nanoscale zero-valent iron (nZVI) with precision milling. Green Chemistry 2009;11(10):1618-1626. GR832225 (Final)
  • Abstract: Green Chemistry-Abstract
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  • Journal Article Li X-Q, Zhang W-X. Iron nanoparticles: the core-shell structure and unique properties for Ni(II) sequestration. Langmuir 2006;22(10):4638-4642. GR832225 (2005)
    GR832225 (2006)
    GR832225 (Final)
    R829625 (Final)
  • Abstract from PubMed
  • Abstract: ACS-Abstract
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  • Journal Article Li X-Q, Elliott DW, Zhang W-X. Zero-valent iron nanoparticles for abatement of environmental pollutants: materials and engineering aspects. Critical Reviews in Solid State and Materials Sciences 2006;31(4):111-122. GR832225 (2006)
    GR832225 (Final)
  • Full-text: gitech-Full Text PDF
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  • Abstract: Taylor&Francis-Abstract
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  • Journal Article Li X-Q, Brown DG, Zhang W-X. Stabilization of biosolids with nanoscale zero-valent iron (nZVI). Journal of Nanoparticle Research 2007;9(2):233-243. GR832225 (2006)
    GR832225 (Final)
  • Full-text: Springer-Full Text PDF
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  • Abstract: Springer-Abstract
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  • Journal Article Li X-Q, Zhang W-X. Sequestration of metal cations with zerovalent iron nanoparticles – a study with high resolution X-ray photoelectron spectroscopy (HR-XPS). Journal of Physical Chemistry C 2007;111(19):6939-6946. GR832225 (2006)
    GR832225 (Final)
  • Abstract: ACS-Abstract
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  • Journal Article Li X-Q, Cao J, Zhang W-X. Stoichiometry of Cr(VI) immobilization using nanoscale zerovalent iron (nZVI): a study with high-resolution X-ray photoelectron spectroscopy (HR-XPS). Industrial & Engineering Chemistry Research 2008;47(7):2131-2139. GR832225 (Final)
  • Abstract: ACS-Abstract
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  • Journal Article Lien H-L, Zhang W-X. Hydrodechlorination of chlorinated ethanes by nanoscale Pd/Fe bimetallic particles. Journal of Environmental Engineering-ASCE 2005;131(1):4-10. GR832225 (2005)
    GR832225 (2006)
    GR832225 (Final)
    R829625 (2003)
    R829625 (Final)
  • Full-text: National University of Kaohsiung-Full Text PDF
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  • Abstract: ASCE-Abstract
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  • Journal Article Lien H-L, Zhang W-X. Removal of methyl tert-butyl ether (MTBE) with Nafion. Journal of Hazardous Materials 2007;144(1-2):194-199. GR832225 (2006)
    GR832225 (Final)
  • Abstract from PubMed
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  • Abstract: ScienceDirect-Abstract
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  • Journal Article Lien H-L, Zhang W-X. Nanoscale Pd/Fe bimetallic particles: catalytic effects of palladium on hydrodechlorination. Applied Catalysis B: Environmental 2007;77(1-2):110-116. GR832225 (Final)
  • Full-text: National University of Kaohsiung-Full Text PDF
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  • Abstract: ScienceDirect-Abstract
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  • Journal Article Lien H-L, Elliott DW, Sun Y-P, Zhang W-X. Recent progress in zero-valent iron nanoparticles for groundwater remediation. Journal of Environmental Engineering and Management 2006;16(6):371-380. GR832225 (2006)
    GR832225 (Final)
  • Full-text: JEEM-Full Text PDF
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  • Abstract: JEEM-Abstract
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  • Journal Article Ma L, Zhang W-X. Enhanced biological treatment of industrial wastewater with bimetallic zero-valent iron. Environmental Science & Technology 2008;42(15):5384-5389. GR832225 (Final)
  • Abstract from PubMed
  • Full-text: Asean Environment-Full Text PDF
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  • Abstract: ACS-Abstract
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  • Journal Article Mace C, Desrocher S, Gheorghiu F, Kane A, Pupeza M, Cernik M, Kvapil P, Venkatakrishnan R, Zhang W-X. Nanotechnology and groundwater remediation: a step forward in technology understanding. Remediation 2006;16(2):23-33. GR832225 (2005)
    GR832225 (2006)
    GR832225 (Final)
    R829625 (Final)
  • Abstract: Wiley Online-Abstract
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  • Journal Article Martin JE, Herzing AA, Yan W, Li X-Q, Koel BE, Kiely CJ, Zhang W-X. Determination of the oxide layer thickness in core-shell zerovalent iron nanoparticles. Langmuir 2008;24(8):4329-4334. GR832225 (Final)
  • Abstract from PubMed
  • Abstract: ACS-Abstract
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  • Journal Article Ramos MAV, Yan W, Li X-Q, Koel BE, Zhang W-X. Simultaneous oxidation and reduction of arsenic by zero-valent iron nanoparticles: understanding the significance of the core-shell structure. Journal of Physical Chemistry C 2009;113(33):14591-14594. GR832225 (Final)
  • Full-text: Princeton University-Full Text PDF
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  • Abstract: ACS-Abstract
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  • Journal Article Sun Y-P, Li X-Q, Zhang W-X, Wang HP. A method for the preparation of stable dispersion of zero-valent iron nanoparticles. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2007;308(1-3):60-66. GR832225 (2006)
    GR832225 (Final)
  • Abstract: ScienceDirect-Abstract
    Exit
  • Journal Article Sun Y-P, Li X-Q, Cao JS, Zhang W-X, Wang HP. Characterization of zero-valent iron nanoparticles. Advances in Colloid and Interface Science 2006;120(1-3):47-56. GR832225 (2005)
    GR832225 (2006)
    GR832225 (Final)
    R829625 (Final)
  • Abstract from PubMed
  • Full-text: National Cheng Kung University-Full Text PDF
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Journal Article Yan W, Herzing AA, Li X-Q, Kiely CJ, Zhang W-X. Structural evolution of Pd-doped nanoscale zero-valent iron (nZVI) in aqueous media and implications for particle aging and reactivity. Environmental Science & Technology 2010;44(11):4288-4294. GR832225 (Final)
  • Abstract from PubMed
  • Full-text: NIST-Full Text PDF
  • Abstract: ACS-Abstract
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  • Journal Article Zhang W-X, Karn B. Nanoscale environmental science and technology: challenges and opportunities. Environmental Science & Technology 2005;39(5):94A-95A. GR832225 (2005)
    GR832225 (2006)
    GR832225 (Final)
    R829625 (Final)
  • Abstract from PubMed
  • Full-text: ES&T-Full Text PDF
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  • Abstract: ES&T-Abstract
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  • Journal Article Zhang W-X, Elliott DW. Applications of iron nanoparticles for groundwater remediation. Remediation 2006;16(2):7-21. GR832225 (2005)
    GR832225 (2006)
    GR832225 (Final)
    R829625 (Final)
  • Abstract: Wiley-Abstract
    Exit
  • Supplemental Keywords:

    ground water, nanoparticles, nanotechnology, organics, PBTs, pesticides, remediation, soil, sediments;, RFA, Scientific Discipline, Waste, Sustainable Industry/Business, Remediation, Environmental Chemistry, Sustainable Environment, Technology for Sustainable Environment, Biochemistry, New/Innovative technologies, Environmental Engineering, nanoparticle remediation, decontamination, bioengineering, persistant bioaccumulative toxic compounds, biodegradation, remediation technologies, nanotechnology, environmental sustainability, bio-engineering, nanocatalysts, environmentally applicable nanoparticles, biotechnology, sustainability, nanoscale bimetallic particles, innovative technologies, nanoparticle based remediation

    Progress and Final Reports:

    Original Abstract
  • 2005 Progress Report
  • 2006 Progress Report
  • 2007