scholarly journals INVESTIGATION OF REMOVAL OF HEXAVALENT CHROMIUM AND DIVALENT COBALT FROM AQUEOUS SOLUTIONS BY ORGANO-MONTMORILLONITE SUPPORTED IRON NANOPARTICLES

2016 ◽  
Vol 5 ◽  
pp. 81-88 ◽  
Author(s):  
Viktoriia Prus ◽  
Nataliya Zhdanyuk
Keyword(s):  
Environmental Remediation ◽  
Iron Nanoparticles ◽  
Removal Rate ◽  
Environmental Pollutants ◽  
Zero Valent Iron ◽  
Hexadecyltrimethylammonium Bromide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanoscale Zero Valent Iron ◽  
Supported Iron

A new class of nanoscale zero-valent iron particles supported on natural montmorillonite and organo-montmorillonite were synthesized and the feasibility for the removal of and was examined through laboratory batch test. The X – ray diffraction (XRD) and Fourier Transform Infrared spectrum (FTIR) investigation has been applied for determination of the particle size and mechanism of remediation process. The aim of this study was to enhance the reduction of persistent environmental pollutants difficult to degrade by immobilization of nanoscale zero-valent iron on an organo-montmorillonite. Batch experiments indicated that the reduction of both and was much greater with organo-montmorillonite supported iron nanoparticles reaching removal rate up to 98.5% and 95.6% respectively at the initial metal concentrations of 50 mg/L. Iron and crystalline iron oxide were detected by X-ray diffraction patterns. In the FTIR spectrum, CH2 groups were found in iron nanoparticles supported on hexadecyltrimethylammonium bromide modified montmorillonite (HDTMA-Mont/nZVI) particles but were significantly weakened in comparison with the spectrum of hexadecyl trimethylammonium bromide (HDTMA). Other factor that affects the efficiency of heavy metals removal such as pH values was also investigated. The obtained data and review of the current literature have given the opportunity to figure out the mechanisms of and removal which may thus promote the industrial application of nZVI technique in environmental remediation by changing the hydrophilic – hydrophobic properties of source systems.

scholarly journals Removal efficiency of hexavalent chromium from wastewater using starch-stabilized nanoscale zero-valent iron

2019 ◽  
Vol 80 (6) ◽  
pp. 1076-1084 ◽  
Author(s):  
Hualin Chen ◽  
Huajun Xie ◽  
Jiangmin Zhou ◽  
Yueliang Tao ◽  
Yongpu Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Reactivity ◽  
Zero Valent Iron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phase Reduction ◽  
Nanoscale Zero Valent Iron ◽  
Removal Efficiencies ◽  
Ph Range ◽  
Uniform Particle Size

Abstract In this study, starch-stabilized nanoscale zero-valent iron (S-nZVI) was produced using the liquid-phase reduction method. It was used to remove chromium from wastewater, and compared to a commercial nanoscale zero-valent iron (C-nZVI). Both nZVIs were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The characterization results showed that S-nZVI had smaller particles and a more uniform particle size distribution than C-nZVI. Both nZVIs showed a core-shell structure with the Fe0 core prominently surrounded by less iron oxides of Fe2+ and Fe3+. The optimal application methods to remove Cr(VI) from wastewater were also explored. The results showed that both the removal efficiencies of total Cr and Cr(VI) increased with increases in the addition of nZVIs, while the removal efficiencies of total Cr and Cr(VI) by S-nZVI were clearly higher than that of C-nZVI, especially in a low pH range (pH = 1.0–6.0). This research indicated that starch-stabilized nanoscale zero-valent iron is a valuable material to remove heavy metals from wastewater due to its stability and high reactivity.

scholarly journals Simultaneous adsorption and reduction of hexavalent chromium on biochar-supported nanoscale zero-valent iron (nZVI) in aqueous solution

2020 ◽  
Vol 82 (7) ◽  
pp. 1339-1349
Author(s):  
Fengfeng Ma ◽  
Bakunzibake Philippe ◽  
Baowei Zhao ◽  
Jingru Diao ◽  
Jian Li
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Zero Valent Iron ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
Nanoscale Zero Valent Iron ◽  
Pseudo Second Order

Abstract Flax straw biochar (FSBC)-supported nanoscale zero-valent iron (nZVI) composite (nZVI-FSBC) combining the advantages of nZVI and biochar was synthesized and tested for Cr(VI) removal efficiency from aqueous solution. Surface morphology and structure of FSBC and nZVI-FSBC were characterized by scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller techniques, which help to clarify the mechanism of Cr(VI) removal from aqueous solution. The adsorption of Cr(VI) onto FSBC and nZVI-FSBC was best described by the pseudo-second-order and the Sips model. Compared with FSBC, nZVI-FSBC remarkably improved the performance in removing Cr(VI) under identical experimental conditions. Due to the collaborative effect of adsorption and reduction of nZVI-FSBC, the adsorption capacity of nZVI-FSBC for Cr(VI) is up to 186.99 mg/g. The results obtained by XPS, XRD, and FTIR confirmed that adsorption and reduction dominated the processes of Cr(VI) removal by nZVI-FSBC. As a supporter, FSBC not only improved the dispersion of nZVI, but also undertook the adsorption task of Cr(VI) removal. The surface oxygen-containing functional groups of nZVI-FSBC mainly participated in the adsorption part, and the nZVI promoted the Cr(VI) removal through the redox reactions. These observations indicated that the nZVI-FSBC can be considered as potential adsorbents to remove Cr(VI) for environment remediation.

Preparation, Characterization and their Performance of the Supported Nanoscale Zero-Valent Iron Materials with Different Iron Contents

2012 ◽  
Vol 573-574 ◽  
pp. 155-162
Author(s):  
Zhi Hua Pang ◽  
Xiao Shan Jia ◽  
Kai Liu ◽  
Zhen Xing Wang ◽  
Qi Jing Luo ◽  
...  
Keyword(s):  
Ferrous Sulfate ◽  
High Performance ◽  
Particle Diameter ◽  
Zero Valent Iron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Modified Montmorillonite ◽  
Nanoscale Zero Valent Iron ◽  
Visible Effect

Taking the organic modified montmorillonite as a carrier and dispersant, the supported nanoscale zero-valent iron materials with different iron contents were synthesized through the ferrous sulfate (FeSO4) and the sodium borohydride (NaBH4) in it. The structure and morphology of the materials were characterized by X-ray diffraction(XRD) and scanning electron microscopy(SEM). Finally, the performances of the supported nanoscale zero-valent iron were studied by high-performance liquid chromatography to determine the adsorption and degradation of 4-chlorophenol. The results indicate that the supported nanoscale zero-valent iron was well dispersed,different iron dosages imposed a visible effect on the morphology and particle diameter of iron;the degradation of 4-chlorophenol resulted from adsorption and degradation processes. Materials with different iron contents exhibited significantly different performance levels in terms of 4-chlorophenol adsorption and degradation.

scholarly journals Ti/RuO2-IrO2-SnO2 Anode for Electrochemical Degradation of Pollutants in Pharmaceutical Wastewater: Optimization and Degradation Performances

2020 ◽  
Vol 13 (1) ◽  
pp. 126
Author(s):  
Guozhen Zhang ◽  
Xingxing Huang ◽  
Jinye Ma ◽  
Fuping Wu ◽  
Tianhong Zhou
Keyword(s):  
Removal Rate ◽  
Inorganic Compounds ◽  
Oxide Coating ◽  
X Ray Diffraction ◽  
Pharmaceutical Wastewater ◽  
High Concentration ◽  
Dimensionally Stable Anodes ◽  
X Ray ◽  
Initial Ph ◽  
Cod Removal Rate

Electrochemical oxidation technology is an effective technique to treat high-concentration wastewater, which can directly oxidize refractory pollutants into simple inorganic compounds such as H2O and CO2. In this work, two-dimensionally stable anodes, Ti/RuO2-IrO2-SnO2, have been developed in order to degrade organic pollutants from pharmaceutical wastewater. Characterization by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) showed that the oxide coating was successfully fabricated on the Ti plate surface. Electrocatalytic oxidation conditions of high concentration pharmaceutical wastewater was discussed and optimized, and the best results showed that the COD removal rate was 95.92% with the energy consumption was 58.09 kW·h/kgCOD under the electrode distance of 3 cm, current density of 8 mA/cm2, initial pH of 2, and air flow of 18 L/min.

Preparation of xanthated bentonite and its removal behavior for Pb(II) ions

2010 ◽  
Vol 61 (5) ◽  
pp. 1235-1243 ◽  
Author(s):  
Y. F. He ◽  
F. R. Li ◽  
R. M. Wang ◽  
F. Y. Li ◽  
Y. Wang ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Particle Size Analysis ◽  
Lead Ions ◽  
Size Analysis ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Xanthate was successfully grafted onto bentonite by a relatively simple solution reaction. The obtained xanthated bentonite (XBent) was characterized by FT-IR spectrophotometer, thermogravimetric analysis (TG), particle size analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). XBent acting as a type of environmentally friendly adsorbent was applied to remove lead ions from aqueous solutions. The optimum conditions were as follows: [Pb2 + ] = 500 mg L−1, [XBent] = 2 g L−1, pH = 5.0; oscillating 60 min under 200 rpm at 25°C. The removal rate of lead was up to 99.9%. It was found that the lead(II) ions—XBent adsorption isotherm model fitted well to the Freundlich isotherm. The adsorption mechanism was also investigated by SEM and XRD, which concluded that lead ions were complexed or chelated with XBent. XBent appears to have potential to be used later in water treatment as a type of inorganic polymer reagent.

scholarly journals The Use of Tailings to Make Glass as an Alternative for Sustainable Environmental Remediation: The Case of Osor, Catalonia, Spain

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 819
Author(s):  
Pura Alfonso ◽  
Oriol Tomasa ◽  
Luis Miguel Domenech ◽  
Maite Garcia-Valles ◽  
Salvador Martinez ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Toxic Elements ◽  
Glass Structure ◽  
Glass Production ◽  
Potentially Toxic Elements ◽  
Raw Material ◽  
Waste Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Melting Temperatures

Tailings from the Osor fluorite mines release large amounts of potentially toxic elements into the environment. This work is a proposal to remove these waste materials and use them as a raw material in the manufacture of glass. The chemical composition of the tailings was determined by X-ray fluorescence and the mineralogy by X-ray diffraction. Waste materials have SiO2, Al2O3 and CaO contents suitable for a glass production, but Na as NaCO3 has to be added. Two glass formulations, with 80–90% of the residue and 10–20% Na2CO3, have been produced. The crystallization temperatures, obtained by differential thermal analysis, were 875 and 901 °C, and the melting temperatures were 1220 and 1215 °C for the G80-20 and G90-10 glasses, respectively. The transition temperatures of glass were 637 and 628 °C. The crystalline phases formed in the thermal treatment to produce devitrification were nepheline, plagioclase and diopside in the G80-20 glass, and plagioclase and akermanite-gehlenite in the G90-10 glass. The temperatures for the fixed viscosity points, the working temperatures and the coefficient of expansion were obtained. The chemical stability of the glass was tested and results indicate that the potentially toxic elements of the tailings were incorporated into the glass structure.

Removeal of Arsenic(III) from Water by Using a New Class of Zero-Valent Iron Modified Mesoporous Silica Molecular Sieves SBA-15

2011 ◽  
Vol 356-360 ◽  
pp. 423-429
Author(s):  
Meng Ye ◽  
Jin Huang ◽  
Rui Chen ◽  
Qi Zhuang He
Keyword(s):  
Molecular Sieves ◽  
Cost Effective ◽  
Zero Valent Iron ◽  
Preparation Process ◽  
X Ray Diffraction ◽  
Wet Impregnation ◽  
X Ray ◽  
New Class ◽  
Transmission Electron ◽  
Removal Of Arsenic

An elevated arsenic (As) content in groundwater imposes a great threat to people worldwide. Thus, developing new and cost-effective methods to remove As from groundwater and drinking water becomes a priority. Using Zero-Valent iron (ZVI) to remove As from water is a proven technology. In this study, ZVI modified SBA-15 mesoporous silicamolecular sieves (ZVI-SBA-15), was prepared, characterized, and used for removing arsenic from water. Wet impregnation, drying, and calcination steps led to iron inclusion within the mesopores. Iron oxide was reduced to ZVI by NaBH4, and the ZVI modified SBA-15 was obtained. Fourier-transform infrared spectroscopy confirmed the preparation process of the nitrate to oxide forms. The structure of the materials was confirmed by Powder X-ray diffraction. Its data indicated that the structure of ZVI-SBA-15 retained the host SBA-15 structure. Brunauer-Emmett-Teller analysis revealed a decrease in surface area and pore size, indicating ZVI-SBA-15 coating on the inner surfaces. Transmission electron micrographs also confirmed that modified SBA-15 retained the structure of the parent SBA-15 silica.It has a high uptake capability(more than 90 pecent) make it potentially attractive absorbent for the removal of arsenic from water.

Characterization of New Nonstoichiometric Ferroelectric (Li0.95Cu0.15)Ta0.76Nb0.19O3 and Comparative Study With (Li0.95Cu0.15)Ta0.57Nb0.38O3 as Photocatalysts in Microbial Fuel Cells

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
S. Louki ◽  
N. Touach ◽  
A. Benzaouak ◽  
V. M. Ortiz-Martínez ◽  
M. J. Salar-García ◽  
...  
Keyword(s):  
Power Density ◽  
Microbial Fuel Cells ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ferroelectric Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Uv Visible

This work investigates the photocatalytic activity of new ferroelectric material with formula (Li0.95Cu0.15)Ta0.76Nb0.19O3 (LT76) in a single chamber microbial fuel cell (MFC) and compares its performance with the similar photocatalyst (Li0.95Cu0.15)Ta0.57Nb0.38O3 (LT57). The photocatalysts LT76 and LT57 were synthesized by ceramic route under the same conditions, with the same starting materials. The ratio Ta/Nb was fixed at 4.0 and 1.5 for LT76 and LT57, respectively. These phases were characterized by different techniques including X-ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), differential scanning calorimetry (DSC), and ultraviolet (UV)–visible (Vis). The new photocatalyst LT76 presents specific surface area of 0.791 m2/g and Curie temperature of 1197 °C. The photocatalytic efficiency of this material is assessed in terms of wastewater treatment and electricity generation by power density and removal rate of chemical oxygen demand (COD) in the presence of a light source. The values of maximum power density and COD removal were 19.77 mW/m3 and 93%, respectively, for LT76.

A Facile Strategy to Fabricate Nanoscale Zero-Valent Iron Decorated Graphene Oxide Composite for Dechloridation of Trichloroacetic Acid in Water

2018 ◽  
Vol 18 (12) ◽  
pp. 8252-8257 ◽  
Author(s):  
Huixuan Zhang ◽  
Xinyi Zhang ◽  
Ruonan Guo ◽  
Qingfeng Cheng ◽  
Xiuwen Cheng
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Sewage Treatment ◽  
Reduction Process ◽  
Zero Valent Iron ◽  
Chlorinated Organic Compounds ◽  
X Ray ◽  
Transmission Electron ◽  
Nanoscale Zero Valent Iron ◽  
Adsorption Desorption

In this study, nanoscale zero-valent iron decorated graphene oxide (NZVI/GO) composite was fabricated through a reduction process in the presence of sodium borohydride (NaBH4) solution. Subsequently, physicochemical properties of the NZVI/GO composites were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 adsorption/desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transformation infrared spectroscopy (FT-IR) and Raman spectra. Results indicated that Fe species existed in the form of Fe0, which uniformly dispersed on the surface of GO. Furthermore, the performance of NZVI/GO was evaluated by the degradation of tichloroacetic acid (TCAA). TCAA can be rapidly degraded by NZVI/GO. This paper provides a promising strategy to synthesize versatile catalyst which would be potentially applied in sewage treatment to degrade chlorinated organic compounds.

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