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Nalini Sankararamakrishnan - One of the best experts on this subject based on the ideXlab platform.
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removal of antimonite sb iii and antimonate sb v using Zerovalent Iron decorated functionalized carbon nanotubes
RSC Advances, 2016Co-Authors: Shruti Mishra, Jaya Dwivedi, Amar Kumar, Nalini SankararamakrishnanAbstract:Carbon nanotubes (CNT) were synthesized by floating catalytic chemical vapor deposition method using ferrocene and benzene as hydrocarbon source. The prepared CNTs were oxidized with nitric acid (CNT-OX) followed by coating with nano Zerovalent Iron (ZVI) to yield nano ZVI decorated CNTs (CNT-Fe(0)). The prepared adsorbents were characterized by various techniques. Using spectral techniques like infra red, Raman and X-ray photoelectron spectroscopy, the mechanism of adsorption between the adsorbent and adsorbate has been postulated. Using CNT-Fe(0) at pH 5, the maximum adsorption capacity of Sb(III) and Sb(V) was found to be 250 mg g−1. The high sorption capacity could be attributed to the high surface area of the prepared CNTs and the reactive nature of the nano Zerovalent Iron particles on CNTs. A pseudo second order kinetics was followed by CNT-Fe(0) with both Sb(III) and Sb(V) with a rate constant of 0.0015 and 0.0011 mg g−1 min−1 respectively. The interference effect of various ions on the adsorption of Sb(III)/Sb(V) are as follows: PO43− > SiO32− > ASO43− > SO42−, NO3− > Cl−, humic acid. The recyclability of the sorbent was demonstrated for 5 cycles using 0.05 M HCl as desorbent. The versatility of the adsorbent was demonstrated by the removal capacity of both Sb(III) and Sb(V) at parts per billion levels from nuclear decontamination formulation (NAC) and tap water matrix as well.
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Zerovalent Iron encapsulated chitosan nanospheres a novel adsorbent for the removal of total inorganic arsenic from aqueous systems
Chemosphere, 2012Co-Authors: Anjali Gupta, Mohammad Yunus, Nalini SankararamakrishnanAbstract:Abstract Evaluation of Chitosan Zerovalent Iron Nanoparticle (CIN) towards arsenic removal is presented. Addition of chitosan enhances the stability of Fe(0) nano particle. Prepared adsorbent was characterized by FT-IR, SEM EDX, BET and XRD. It was found that, with an initial dose rate of 0.5 g L−1, concentrations of As (III) and As (V) were reduced from 2 mg L−1 to
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Zerovalent Iron encapsulated chitosan nanospheres – A novel adsorbent for the removal of total inorganic Arsenic from aqueous systems
Chemosphere, 2011Co-Authors: Anjali Gupta, Mohammad Yunus, Nalini SankararamakrishnanAbstract:Abstract Evaluation of Chitosan Zerovalent Iron Nanoparticle (CIN) towards arsenic removal is presented. Addition of chitosan enhances the stability of Fe(0) nano particle. Prepared adsorbent was characterized by FT-IR, SEM EDX, BET and XRD. It was found that, with an initial dose rate of 0.5 g L−1, concentrations of As (III) and As (V) were reduced from 2 mg L−1 to
Anjali Gupta - One of the best experts on this subject based on the ideXlab platform.
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Zerovalent Iron encapsulated chitosan nanospheres a novel adsorbent for the removal of total inorganic arsenic from aqueous systems
Chemosphere, 2012Co-Authors: Anjali Gupta, Mohammad Yunus, Nalini SankararamakrishnanAbstract:Abstract Evaluation of Chitosan Zerovalent Iron Nanoparticle (CIN) towards arsenic removal is presented. Addition of chitosan enhances the stability of Fe(0) nano particle. Prepared adsorbent was characterized by FT-IR, SEM EDX, BET and XRD. It was found that, with an initial dose rate of 0.5 g L−1, concentrations of As (III) and As (V) were reduced from 2 mg L−1 to
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Zerovalent Iron encapsulated chitosan nanospheres – A novel adsorbent for the removal of total inorganic Arsenic from aqueous systems
Chemosphere, 2011Co-Authors: Anjali Gupta, Mohammad Yunus, Nalini SankararamakrishnanAbstract:Abstract Evaluation of Chitosan Zerovalent Iron Nanoparticle (CIN) towards arsenic removal is presented. Addition of chitosan enhances the stability of Fe(0) nano particle. Prepared adsorbent was characterized by FT-IR, SEM EDX, BET and XRD. It was found that, with an initial dose rate of 0.5 g L−1, concentrations of As (III) and As (V) were reduced from 2 mg L−1 to
Gregory V Lowry - One of the best experts on this subject based on the ideXlab platform.
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Quantifying the efficiency and selectivity of organohalide dechlorination by Zerovalent Iron.
Environmental science. Processes & impacts, 2020Co-Authors: Li Gong, Paul G. Tratnyek, Dimin Fan, Gregory V LowryAbstract:The efficiency and selectivity of Zerovalent Iron-based treatments for organohalide contaminated groundwater can be quantified by accounting for redistribution of electrons derived from oxidation of Fe0. Several types of efficiency are reviewed, including (i) the efficiency of Fe(0) utilization, eFe(0), (ii) the electron efficiency of target contaminant reduction, ee, and (iii) the electron efficiency of natural reductant demand (NRD) involving H2O, O2, and co-contaminants such as nitrate, eNRD. Selectivity can then be calculated by using ee/eNRD. Of particular interest is ee and the key to its determination is measuring the total quantity of electrons provided by Fe0 oxidation, which can be based on either the loss of Fe(0), the formation of Fe(II)/Fe(III), or the composition of the total reaction products. Recently, many data have accumulated on ee for the treatment of various chlorinated solvents (esp. trichloroethylene, TCE) by Zerovalent Iron (ZVI), and analysis of these data shows that ZVI particle properties (e.g., stabilization with polymers, bimetallic modification, sulfidation, etc.) and other operational factors have variable effects on ee. Of particular interest is that pre-exposure of ZVI to reduced sulfur species (i.e., sulfidation) consistently improves the ee of contaminant reduction, mainly by suppressing the reduction of water.
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Sulfur Dose and Sulfidation Time Affect Reactivity and Selectivity of Post-Sulfidized Nanoscale Zerovalent Iron.
Environmental science & technology, 2019Co-Authors: Zhen Cao, Yan Wang, He Zhou, Zimo Lou, Gregory V LowryAbstract:Exposing nanoscale Zerovalent Iron (NZVI) to dissolved sulfide species improves its performance as a remediation agent. However, the impacts of sulfur dose and sulfidation time on morphology, sulfu...
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Reactivity, Selectivity, and Long-Term Performance of Sulfidized Nanoscale Zerovalent Iron with Different Properties
Environmental science & technology, 2019Co-Authors: Yan Wang, Cindy Weng, Weiliang Bai, Yang Jiao, Ralf Kaegi, Gregory V LowryAbstract:Sulfidized nanoscale Zerovalent Iron (SNZVI) has desirable properties for in situ groundwater remediation. However, there is limited understanding of how the sulfidation type and particle propertie...
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electromagnetic induction of Zerovalent Iron zvi powder and nanoscale Zerovalent Iron nzvi particles enhances dechlorination of trichloroethylene in contaminated groundwater and soil proof of concept
Environmental Science & Technology, 2016Co-Authors: Tanapon Phenrat, Thippawan Thongboot, Gregory V LowryAbstract:This study evaluates the concept of using Zerovalent Iron (ZVI) powder or nanoscale Zerovalent Iron (NZVI) particles in combination with a low frequency (150 kHz) AC electromagnetic field (AC EMF) to effectively remove trichloroethylene (TCE) from groundwater and saturated soils. ZVI and NZVI are ferromagnetic, which can induce heat under applied AC EMF. The heat generated by ZVI and NZVI induction can increase the rate of dechlorination, according to Arrhenius’ equation, and increase the rate of TCE desorption from TCE-sorbed soil. Both dechlorination and TCE desorption enhance the overall TCE removal rate. We evaluated this novel concept in laboratory batch reactors. We found that both ZVI and NZVI can induce heat under applied AC EMF up to 120 °C in 20 min. Using ZVI and NZVI with AC EMF enhanced dechlorination of dissolved TCE (no soil) up to 4.96-fold. In addition to increasing the temperature by ZVI and NZVI induction heating, AC EMF increased intrinsic ZVI and NZVI reactivity, ostensibly due to acc...
Vimlesh Chandra - One of the best experts on this subject based on the ideXlab platform.
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synthesis of nano Zerovalent Iron nanoparticles graphene composite for the treatment of lead contaminated water
Journal of Environmental Management, 2013Co-Authors: Humera Jabeen, Christian K Kemp, Vimlesh ChandraAbstract:Abstract A Nano Zerovalent Iron nanoparticles graphene composite (G-nZVI) was prepared via a sodium borohydride reduction of graphene oxide and Iron chloride under an argon atmosphere. Powder X-ray diffraction patterns showed the formation of the magnetic graphene/nanoscale-Zerovalent-Iron (G-nZVI) composites and bare nanoscale-Zerovalent-Iron (nZVI) particles. TEM analysis shows the formation of ∼10 nm particles. Adsorption experiments show a maximum Pb(II) adsorption capacity for the G-nZVI composite with 6 wt% graphene oxide loading. Additionally the effects of pH, temperature, contact time, ionic strength and initial metal ion concentration on Pb(II) ion removal were studied. X-ray photoelectron spectroscopy analysis after adsorption results confirmed the composite's ability to adsorb and immobilize lead more efficiently in its Zerovalent and bivalent forms, as compared to bare Iron nanoparticles. The adsorption of Pb(II) ions fit a pseudo-second-order kinetic model, and adsorption isotherms can be described using the Freundlich equations. G-nZVI shows great potential as an efficient adsorbent for lead immobilization from water, as it exhibits stability, reducing power, a large surface area, and magnetic separation.
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Synthesis of nano Zerovalent Iron nanoparticles – Graphene composite for the treatment of lead contaminated water
Journal of environmental management, 2013Co-Authors: Humera Jabeen, K. Christian Kemp, Vimlesh ChandraAbstract:Abstract A Nano Zerovalent Iron nanoparticles graphene composite (G-nZVI) was prepared via a sodium borohydride reduction of graphene oxide and Iron chloride under an argon atmosphere. Powder X-ray diffraction patterns showed the formation of the magnetic graphene/nanoscale-Zerovalent-Iron (G-nZVI) composites and bare nanoscale-Zerovalent-Iron (nZVI) particles. TEM analysis shows the formation of ∼10 nm particles. Adsorption experiments show a maximum Pb(II) adsorption capacity for the G-nZVI composite with 6 wt% graphene oxide loading. Additionally the effects of pH, temperature, contact time, ionic strength and initial metal ion concentration on Pb(II) ion removal were studied. X-ray photoelectron spectroscopy analysis after adsorption results confirmed the composite's ability to adsorb and immobilize lead more efficiently in its Zerovalent and bivalent forms, as compared to bare Iron nanoparticles. The adsorption of Pb(II) ions fit a pseudo-second-order kinetic model, and adsorption isotherms can be described using the Freundlich equations. G-nZVI shows great potential as an efficient adsorbent for lead immobilization from water, as it exhibits stability, reducing power, a large surface area, and magnetic separation.
Yalei Zhang - One of the best experts on this subject based on the ideXlab platform.
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enhanced oxidative and adsorptive removal of diclofenac in heterogeneous fenton like reaction with sulfide modified nanoscale Zerovalent Iron
Environmental Science & Technology, 2018Co-Authors: David Jassby, Xuefei Zhou, Shikun Song, Hongying Zhao, Jan Filip, Eleni Petala, Yalei ZhangAbstract:Sulfidation of nanoscale Zerovalent Iron (nZVI) has shown some fundamental improvements on reactivity and selectivity toward pollutants in dissolved-oxygen (DO)-stimulated Fenton-like reaction systems (DO/S-nZVI system). However, the pristine microstructure of sulfide-modified nanoscale Zerovalent Iron (S-nZVI) remains uncovered. In addition, the relationship between pollutant removal and the oxidation of the S-nZVI is largely unknown. The present study confirms that sulfidation not only imparts sulfide and sulfate groups onto the surface of the nanoparticle (both on the oxide shell and on flake-like structures) but also introduces sulfur into the Fe(0) core region. Sulfidation greatly inhibits the four-electron transfer pathway between Fe(0) and oxygen but facilitates the electron transfer from Fe(0) to surface-bound Fe(III) and consecutive single-electron transfer for the generation of H2O2 and hydroxyl radical. In the DO/S-nZVI system, slight sulfidation (S/Fe molar ratio = 0.1) is able to nearly doubl...
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Magnetic sulfide-modified nanoscale Zerovalent Iron (S-nZVI) for dissolved metal ion removal
Water research, 2015Co-Authors: Adeyemi S. Adeleye, Arturo A. Keller, Yuxiong Huang, Chaomeng Dai, Xuefei Zhou, Yalei ZhangAbstract:Sulfide-modified nanoscale Zerovalent Iron (S-nZVI) is attracting a lot of attention due to its ease of production and high reactivity with organic pollutants. However, its structure is still poorly understood and its potential application in heavy metal remediation has not been explored. Herein, the structure of S-nZVI and its cadmium (Cd) removal performance under different aqueous conditions were carefully investigated. Transmission electron microscopy (TEM) with an energy-dispersive X-ray spectroscopy (EDS) analysis suggested that sulfur was incorporated into the Zerovalent Iron core. Scanning electron microscopy (SEM) with EDS analysis demonstrated that sulfur was also homogeneously distributed within the nanoparticles. When the concentration of Na2S2O4 was increased during synthesis, a flake-like structure (FeSx) increased significantly. S-nZVI had an optimal Cd removal capacity of 85 mg/g, which was >100% higher than for pristine nZVI. Even at pH 5, over 95% removal efficiency was observed, indicating sulfide compounds played a crucial role in metal ion removal and particle chemical stability. Oxygen impaired the structure of S-nZVI but enhanced Cd removal capacity to about 120 mg/g. Particle aging had no negative effect on removal capacity of S-nZVI, and Cd-containing mixtures remained stable in a two months experiment. S-nZVI can efficiently sequester dissolved metal ions from different contaminated water matrices.
