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The Feasibility Of Using Zero Valent Iron For The Remediation Of Ethanethiol Contaminated Ground Water
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Book Synopsis The Feasibility of Using Zero-valent Iron for the Remediation of Ethanethiol Contaminated Ground Water by : Benjamin L. Wear
Download or read book The Feasibility of Using Zero-valent Iron for the Remediation of Ethanethiol Contaminated Ground Water written by Benjamin L. Wear and published by . This book was released on 1998 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Electrochemical Remediation of Radionuclide- and Trichloroethene-contaminated Groundwater Using Zero-valent Iron/iron Oxides and Mineralogical Characterization of Iron Hydroxides Formed from Zero-valent Iron by : Yul Roh
Download or read book Electrochemical Remediation of Radionuclide- and Trichloroethene-contaminated Groundwater Using Zero-valent Iron/iron Oxides and Mineralogical Characterization of Iron Hydroxides Formed from Zero-valent Iron written by Yul Roh and published by . This book was released on 1998 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Effect of Groundwater Biogeochemistry on Zero Valent Iron Nanoparticles by : Sai Rajasekar Chandrasekar Rajajayavel
Download or read book Effect of Groundwater Biogeochemistry on Zero Valent Iron Nanoparticles written by Sai Rajasekar Chandrasekar Rajajayavel and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Accidental spills and past improper disposal practices of chlorinated solvents have led to widespread soil and groundwater contamination. Drinking water standards for trichloroethylene (TCE) and many other chlorinated organic contaminants are in the range of 5 μg/L and these compounds have received extensive regulatory attention because these compounds are often carcinogenic and neurotoxic. Direct injection of reactive nanoscale zerovalent iron particles (NZVI) is considered to be a promising approach for remediation of chlorinated compounds. NZVI is a strong reducing agent that can effectively transform TCE and other chlorinated organic compounds to non-toxic end products. The objective of the research was to assess various biogeochemical conditions on the reactivity of iron nanoparticles in particular sulfidation of NZVI for remediation of TCE. In addition, the feasibility of coupled NZVI-based remediation and bioremediation using polymer-coated bimetallic NZVI and a dechlorinating mixed culture consortia (KB-1) was investigated. We demonstrated that the extent of sulfidation of NZVI enhances the rate of dechlorination of TCE compared to non-sulfidated NZVI, and this enhancement depends on the Fe/S molar ratio of the sulfidated NZVI particles. Batch experiments where TCE was reacted with NZVI sulfidated to different extents (Fe/S molar ratios 0.62 to 66) showed that the surface-area normalized first-order TCE degradation rate constant increased 40 fold compared to non-sulfidated NZVI. FX-ray photoelectron spectroscopy analyses showed formation of a surface layer of FeS and FeS2. This indicates sulfide ions reacted with NZVI iron sulfide on surface of S-NZVI. We propose that more electrons are preferentially conducted from sulfidated NZVI than from unamended NZVI to TCE, likely because of greater binding affinity of TCE on the reactive sites of the iron sulfide outer layer. Aging of sulfidated iron nanoparticles (S-NZVI) and their influence on rate of TCE dechlorination was compared to the aged non-sulfidated NZVI. Long-term experiments indicate that pseudo-first order H2 evolution rate constant for non-sulfidated NZVI was 0.092 ± 0.005 d-1 and was significantly higher than the S-NZVI (Fe/S=25) at 0.051 ± 0.005 h-1. This difference in hydrogen evolved corresponds to the amount of reactive Fe(0) consumed in the absence of TCE. To further support, the efficacy of long-term reactivity S-NZVI batch TCE degradation experiment with anaerobically aged S-NZVI (40 days) degraded significantly more TCE than the non-sulfidated NZVI. Bimetallic, palladium-doped iron nanoparticles (Pd-NZVI) are capable of rapid transformation of higher initial TCE concentration, and the ability to form rapid H2 (electron donor for bacteria) may facilitate TCE biodegradation. Dehalococcoides are the only species of bacteria that are capable of degrading TCE completely to ethene under anaerobic conditions. Therefore, we investigated the interaction of carboxymethyl cellulose (CMC) stabilized palladium (Pd-NZVI) on the dechlorinating mixed culture KB-1 for reductive dechlorination of 1, 2 dichloroethane (DCA). Results suggest that systems with CMC alone as a sole carbon source and electron donor were capable of degrading 1, 2-DCA, and methane formation. The microcosms with KB-1 and polymer coated Pd-NZVI degraded 1, 2-DCA at a significantly higher rate constant compared to KB-1 and CMC systems. In addition, methanogenesis by KB-1 showed no statistically significant difference in the methane formation rate constants between Pd-CMC-NZVI and CMC only systems.Overall, this research demonstrates NZVI reactivity towards TCE and its longevity (efficacy) under anaerobic conditions can be enhanced with sulfidation. In addition, this research also shows that CMC stabilized bimetallic NZVI, is not inhibitory to Dehalococcoides spp. and could promote complete bioremediation." --
Book Synopsis Use of Zero-valent Iron as a Treatment Medium for Ground Water Remediation by : Xueyuan Yu
Download or read book Use of Zero-valent Iron as a Treatment Medium for Ground Water Remediation written by Xueyuan Yu and published by . This book was released on 2005 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fundamental Studies of the Removal of Contaminants from Ground and Waste Waters Via Reduction by Zero-Valent Metals by :
Download or read book Fundamental Studies of the Removal of Contaminants from Ground and Waste Waters Via Reduction by Zero-Valent Metals written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contaminated groundwater and surface waters are a problem throughout the United States and the world. In many instances, the types of contamination can be directly attributed to man's actions. For instance, the burial of chemical wastes, casual disposal of solvents in unlined pits, and the development of irrigated agriculture have all contributed to groundwater and surface water contamination. The kinds of contaminants include chlorinated solvents and toxic trace elements (including radioisotopes) that are soluble and mobile in soils and aquifers. Oxyanions of uranium, selenium, chromium, arsenic, technetium, and chlorine (as perchlorate) are frequently found as contaminants on many DOE sites. Uranium is a particularly widespread contaminant at most DOE sites including Oak Ridge, Rocky Flats, Hanford, Idaho (INEEL), and Fernald. The uranium contamination is associated with mining and milling of uranium ore (UMTRA sites), isotope separation and enrichment, and mixed waste and TRU waste burial. In addition, the careless disposal of halogenated solvents, such as carbon tetrachloride and trichloroethylene, has further contaminated many groundwaters at these sites. A potential remediation method for many of these oxyanions and chlorinated-solvents is to react the contaminated water with zero-valent iron. In this reaction, the iron serves as both an electron source and as a catalyst. Elemental iron is already being used on an experimental basis at many DOE sites. Both in situ reactive barriers and above-ground reactors are being developed for this purpose. However, the design and operation of these treatment systems requires a detailed process-level understanding of the interactions between the contaminants and the iron surfaces. We are performing fundamental investigations of the interactions of the relevant chlorinated solvents and trace element-containing compounds with single- and poly-crystalline Fe surfaces. The aim of this work is to develop th e fundamental physical and chemical understanding that is necessary for the development of cleanup techniques and procedures.
Book Synopsis Use of Zero-valent Metals in In-situ Remediation of Contaminated Ground Water by : Robert W. Gillham
Download or read book Use of Zero-valent Metals in In-situ Remediation of Contaminated Ground Water written by Robert W. Gillham and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Optimization of Nanoscale Zero-valent Iron for the Remediation of Groundwater Contaminants by : Andrew W.E. McPherson
Download or read book Optimization of Nanoscale Zero-valent Iron for the Remediation of Groundwater Contaminants written by Andrew W.E. McPherson and published by . This book was released on 2012 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fundamental Studies of the Removal of Contaminants from Ground and Waste Waters Via Reduction by Zero-valent Metals. 1998 Annual Progress Report by :
Download or read book Fundamental Studies of the Removal of Contaminants from Ground and Waste Waters Via Reduction by Zero-valent Metals. 1998 Annual Progress Report written by and published by . This book was released on 1998 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contaminated groundwater and surface waters are a problem throughout the US and the world. In many instances, the types of contamination can be directly attributed to man''s actions. For instance, the burial of wastes, casual disposal of solvents in unlined pits, and the development of irrigated agriculture have all contributed to groundwater and surface water contamination. The kinds of contaminants include chlorinated solvents and toxic trace elements that are soluble and mobile in soils and aquifers. Oxyanions of selenium, chromium, uranium, arsenic, and chlorine (as perchlorate) are frequently found as contaminants on many DOE sites. In addition, the careless disposal of cleaning solvents, such as carbon tetrachloride and trichloroethylene, has further contaminated many groundwaters at these sites. Oxyanions of selenium, nitrogen, arsenic, vanadium, uranium, chromium, and molybdenum are contaminants in agricultural areas of the Western US. The management of these waters requires treatment to remove the contaminants before reuse or surface water disposal. In one instance in the Central Valley of California, the discharge of selenate-contaminated shallow groundwater to a wildlife refuge caused catastrophic bird deaths and deformities of embryos. A potential remediation method for many of these oxyanions and chlorinated-solvents is to react the contaminated water with zero-valent iron. In this reaction, the iron serves as both an electron source and as a catalyst. Elemental iron is already being used on an experimental basis. Both in-situ reactive barriers and above-ground reactors are being developed for this purpose. However, the design and operation of these treatment systems requires a detailed process-level understanding of the interactions between the contaminants and the iron surfaces. Only limited success has been achieved in the field, partly because the basic surface chemical reactions are not well understood. The authors are performing fundamental investigations of the interactions of the relevant chlorinated solvents, and trace element-containing compounds with single- and poly-crystalline Fe surfaces. The aim of this work is to develop the fundamental physical and chemical understanding that is necessary for the development of cleanup techniques and procedures. As of May 1998, they have performed both bulk chemical measurements of the reduction reactions and surface science studies of model chemical systems. During these first two years of funding, the authors have made significant progress in both areas. Initially, they focused primarily on the reduction of selenate by elemental iron. They also performed some work with chromate, perchlorate, uranyl, and carbon tetrachloride. In the following sections some of the progress is described.
Book Synopsis A Zero-valent Iron (FE0) Packed-bed Treatment Process by : Paul Westerhoff
Download or read book A Zero-valent Iron (FE0) Packed-bed Treatment Process written by Paul Westerhoff and published by American Water Works Association. This book was released on 2001 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Abiotic Remediation of Nitro-Aromatic Groundwater Contaminants by Zero-Valent Iron by : Abinash Agrawal
Download or read book Abiotic Remediation of Nitro-Aromatic Groundwater Contaminants by Zero-Valent Iron written by Abinash Agrawal and published by . This book was released on 1994 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent laboratory and field experiments have shown that some halogenated hydrocarbons undergo rapid reductive dehalogenation with zero-valent iron and the application of this process is being developed for in-situ remediation of contaminated groundwater. However, from can also reduce other organic substances and is commonly used to synthesize reduction products nitro compounds.
Book Synopsis Zero-valent Iron for the in Situ Remediation of Antarctic Contaminated Sites by : Tom M. Statham
Download or read book Zero-valent Iron for the in Situ Remediation of Antarctic Contaminated Sites written by Tom M. Statham and published by . This book was released on 2015 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Zero-valent Iron Reactive Materials for Hazardous Waste and Inorganics Removal by : Irene Man-Chi Lo
Download or read book Zero-valent Iron Reactive Materials for Hazardous Waste and Inorganics Removal written by Irene Man-Chi Lo and published by Amer Society of Civil Engineers. This book was released on 2007 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides up-to-date technical information and state-of-the-art research findings on the use of zero-valent iron reactive materials to remove contaminants frequently found in groundwater.
Book Synopsis Reactivity and Lifetime of Nano-scale Zero-valent Iron for Groundwater Dense Non-aqueous Phase Liquid Remediation by : Yueqiang Liu
Download or read book Reactivity and Lifetime of Nano-scale Zero-valent Iron for Groundwater Dense Non-aqueous Phase Liquid Remediation written by Yueqiang Liu and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis An Evaluation of Zero Valent Iron Reactive Barrier Technology to Reduce High Concentrations of Chlorinated Solvents in Contaminated Groundwater by : Bryan K. Stolte
Download or read book An Evaluation of Zero Valent Iron Reactive Barrier Technology to Reduce High Concentrations of Chlorinated Solvents in Contaminated Groundwater written by Bryan K. Stolte and published by . This book was released on 2002 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Trade-offs in Utilizing of Zero-valent Iron for Synergistic Biotic and Abiotic Reduction of Trichloroethene and Perchlorate in Soil and Groundwater by : Srivatsan Mohana Rangan
Download or read book Trade-offs in Utilizing of Zero-valent Iron for Synergistic Biotic and Abiotic Reduction of Trichloroethene and Perchlorate in Soil and Groundwater written by Srivatsan Mohana Rangan and published by . This book was released on 2017 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: The advantages and challenges of combining zero-valent iron (ZVI) and microbial reduction of trichloroethene (TCE) and perchlorate (ClO4-) in contaminated soil and groundwater are not well understood. The objective of this work was to identify the benefits and limitations of simultaneous application of ZVI and bioaugmentation for detoxification of TCE and ClO4- using conditions relevant to a specific contaminated site. We studied conditions representing a ZVI-injection zone and a downstream zone influenced Fe (II) produced, for simultaneous ZVI and microbial reductive dechlorination applications using bench scale semi-batch microcosm experiments. 16.5 g L-1 ZVI effectively reduced TCE to ethene and ethane but ClO4- was barely reduced. Microbial reductive dechlorination was limited by both ZVI as well as Fe (II) derived from oxidation of ZVI. In the case of TCE, rapid abiotic TCE reduction made the TCE unavailable for the dechlorinating bacteria. In the case of perchlorate, ZVI inhibited the indigenous perchlorate-reducing bacteria present in the soil and groundwater. Further, H2 generated by ZVI reactions stimulated competing microbial processes like sulfate reduction and methanogenesis. In the microcosms representing the ZVI downstream zone (Fe (II) only), we detected accumulation of cis-dichloroethene (cis-DCE) and vinyl chloride (VC) after 56 days. Some ethene also formed under these conditions. In the absence of ZVI or Fe (II), we detected complete TCE dechlorination to ethene and faster rates of ClO4- reduction. The results illustrate potential limitations of combining ZVI with microbial reduction of chlorinated compounds and show the potential that each technology has when applied separately.
Book Synopsis Comparison of Zero-valent Iron and Activated Carbon for Treating Chlorinated Contaminants in Groundwater by : Bina Mukund Indelicato
Download or read book Comparison of Zero-valent Iron and Activated Carbon for Treating Chlorinated Contaminants in Groundwater written by Bina Mukund Indelicato and published by . This book was released on 1998 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Investigations on Mobility of Carbon Colloid Supported Nanoscale Zero-valent Iron (nZVI) for Groundwater Remediation by : Jan Busch
Download or read book Investigations on Mobility of Carbon Colloid Supported Nanoscale Zero-valent Iron (nZVI) for Groundwater Remediation written by Jan Busch and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Injection of nanoscale zero-valent iron (nZVI) is an innovative technology for in situ installation of a permeable reactive barrier in the subsurface. Zerovalent iron (ZVI) is highly reactive with chlorinated hydrocarbons (CHCs) and renders them into less harmful substances. Application of nZVI instead of granular ZVI can increase rates of dechlorination of CHCs by orders of magnitude, due to its higher surface area. This approach is still difficult to apply due to fast agglomeration and sedimentation of colloidal suspensions of nZVI, which leads to very short transport distances. To overcome this issue of limited mobility, polyanionic stabilisers are added to increase surface charge and stability of suspensions. In field experiments maximum transport distances of a few metres were achieved. A new approach, which is investigated in this thesis, is enhanced mobility of nZVI by a more mobile carrier colloid. The investigated composite material consists of activated carbon, which is loaded with nZVI. In this cumulative thesis, transport characteristics of carbon-colloid supported nZVI (c-nZVI) are investigated. Investigations started with column experiments in 40 cm columns filled with various porous media to investigate on physicochemical influences on transport characteristics. The experimental setup was enlarged to a transport experiment in a 1.2-m-sized two-dimensional aquifer tank experiment, which was filled with granular porous media. Further, a field experiment was performed in a natural aquifer system with a targeted transport distance of 5.3 m. Parallel to these investigations, alternative methods for transport observations were investigated by using noninvasive tomographic methods. Experiments using synchrotron radiation and magnetic resonance (MRI) were performed to investigate in situ transport characteristics in a non-destructive way. Results from column experiments show potentially high mobility under environmental relevant conditions. Addition of mono-and bivalent salts, e.g. more than 0.5 mM/L CaCl2, might decrease mobility. Changes in pH to values below 6 can inhibit mobility at all. Measurements of colloid size show changes in the mean particle size by a factor of ten. Measurements of zeta potential revealed an increase of -62 mV to -82 mV. Results from the 2D-aquifer test system suggest strong particle deposition in the first centimetres and only weak straining in the further travel path and no gravitational influence on particle transport. Straining at the beginning of the travel path in the porous medium was observed with tomographic investigations of transport. MRI experiments revealed similar results to the previous experiments, and observations using synchrotron radiation suggest straining of colloids at pore throats. The potential for high transport distances, which was suggested from laboratory experiments, was confirmed in the field experiment, where the transport distance of 5.3 m was reached by at least 10% of injected nZVI. Altogether, transport distances of the investigated carbon-colloid supported nZVI are higher than published results of traditional nZVI
