Coating Iron Oxides on Kaolinite for the Adsorption of Fluoride

2012 ◽  
Vol 479-481 ◽  
pp. 250-254
Author(s):  
Wen Jun Xiang
Keyword(s):  
Iron Oxides ◽  
Freundlich Isotherm ◽  
Zero Point ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fluoride Adsorption ◽  
Adsorption Data ◽  
Co Precipitation

Iron oxides-coated kaolinite (Fe-Kaolinite) was prepared by co-precipitation and indentified using X-ray diffraction (XRD). Moreover, the surface properties and fluoride adsorption characteristics of Fe-Kaolinite were investigated and compared with those of kaolinite. Compared to kaolinite, the BET surface area and surface fractal dimension of Fe-Kaolinite increased significantly. The pH at zero point of charge (pHZPC) of kaolinite and Fe-Kaolinite was 3.16 and 6.24, respectively. In the suspensions of pH 6.0, the fitted maximum adsorption capacity (qmax) for fluoride of kaolinite and Fe-Kaolinite was 1.32 and 5.86 mg/g, respectively. The adsorption data for fluoride by Fe-Kaolinite could be fitted using Freundlich isotherm (R2 =0.987), and Langmuir isotherm was very suitable for describing the fluoride adsorption of kaolinite (R2 =0.991).

scholarly journals COPPER HEXACYANOFERRATE (II): SYNTHESIS, CHARACTERIZATION, AND CESIUM, STRONTIUM ADSORBENT APPLICATION

2021 ◽  
Author(s):  
Dinh Trung Nguyen ◽  
Vu Tram Anh Le ◽  
Dong Phuong Truong ◽  
Thi Dan Thy Kieu ◽  
Tran Thuy Hong Nguyen ◽  
...  
Keyword(s):  
Low Cost ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Copper Hexacyanoferrate ◽  
X Ray ◽  
Transmission Electron ◽  
High Concentrations ◽  
Co Precipitation

Low-cost nanoscale copper hexacyanoferrate (CuHF), a good selective adsorbent for cesium (Cs+) removal, was prepared using the chemical co-precipitation method. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and high-resolution transmission electron microscopy (HR-TEM) were conducted to determine the CuHF morphology. Copper hexacyanoferrate, Cu13[Fe(CN)6]14.(2K).10H2O, has a cubic structure (space group F-43m) in the range of 10-30 nm and a Brunauer-Emmett-Teller (BET) surface area of 462.42 m2/g. The removal of Cs+ and Sr2+ is dependent on pH; the maximum adsorption capacity (qmax) of CuHF is achieved at a pH = 6. From the Langmuir model, qmax = 143.95 mg/g for Cs+ and 79.26 mg/g for Sr2+, respectively. At high concentrations, Na+, Ca2+, and K+ ions have very little effect on Cs+ removal, and Na+ and K+ ions have a higher affinity for removing Sr2+ than Ca2+ at all concentrations. CuHF has a high affinity for alkaline cations in the order: Cs+ > K+ > Na+ > Ca2+ > Sr2+, as proposed and discussed.

scholarly journals Removal of Cesium and Strontium From Radioactive Wastewater by Prussian Blue Nanorods

2022 ◽  
Author(s):  
Chuqing Yao ◽  
Yaodong Dai ◽  
Shuquan Chang ◽  
Haiqian Zhang
Keyword(s):  
Prussian Blue ◽  
Photoelectron Spectroscopy ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Radioactive Wastewater ◽  
Pseudo Second Order ◽  
Co Precipitation ◽  
Solvothermal Methods

Abstract In this work, novel Prussian blue tetragonal nanorods were prepared by template-free solvothermal methods for removal of radionuclide Cs and Sr. It was worth that Prussian blue nanorods exhibited the better adsorption performance than co-precipitation PB or Prussian blue analogue composites. Thermodynamic analysis implied that adsorption process was spontaneous and endothermic which was described well with Langmuir isotherm and pseudo-second-order equation, the maximum adsorption capacity of PB nanorod was estimated to be 194.26 mg g-1 and 256.62 mg g-1 for Cs+ and Sr2+. The adsorption mechanism of Cs+ and Sr2+ was studied by X-ray photoelectron spectroscopy, X-ray diffraction and 57Fe Mössbaure spectroscopy, the results revealed that Cs+ entered in PB crystal to generate a new phase, the most of Sr2+ was trapped in internal crystal and the other exchanged Fe2+. Furthermore, the effect of co-existing ions and pH for PB adsorption process were also investigated. The results suggest that PB nanorods were outstanding candidate for removal of Cs+ and Sr2+ from radioactive wastewater.

Surface Properties and Selenate Adsorption of Hydroxyiron-Vermiculite Complexes

2012 ◽  
Vol 482-484 ◽  
pp. 1201-1204 ◽  
Author(s):  
Shi Yong Wei
Keyword(s):  
Fractal Dimension ◽  
Surface Properties ◽  
Langmuir Isotherm ◽  
Ph Value ◽  
Freundlich Isotherm ◽  
Point Of Zero Charge ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Capacities ◽  
Adsorption Data

Hydroxyiron-vermiculite complexes (Fe-Vermiculite) were prepared and identified using X-ray diffraction (XRD). The surface properties and selenate adsorption characteristics of Fe-Vermiculite were investigated. The specific surface area, surface fractal dimension D value and the pH value of the point of zero charge (pHPZC) of vermiculite were 287.19 m2/g, 2.14, and 2.87, respectively, and those of Fe-Vermiculite were 312.48 m2/g, 2.59, and 5.74, respectively. At pH 5.5, the maximum adsorption capacities (qmax) for selenate of vermiculite and Fe-Vermiculite were 4.36 and 9.12 mg/g, respectively. Langmuir isotherm was very suitable for describing the selenate adsorption of vermiculite (R2 =0.993), and Freundlich isotherm could fit the adsorption data for selenate by Fe-Vermiculite (R2 =0.981).

Effect of Silicon on Phosphorus Adsorption of Two Synthetic Iron Oxides

2013 ◽  
Vol 726-731 ◽  
pp. 325-330
Author(s):  
Ming Da Liu ◽  
Feng Jiang ◽  
Hui Sun ◽  
Dan Yang ◽  
Yu Long Zhang ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Adsorption Equilibrium ◽  
Equilibrium Constants ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Adsorption Method ◽  
Phosphorus Adsorption ◽  
X Ray ◽  
Transmission Electron ◽  
Effects Of Ph

Iron oxides play an important role in controlling P activity and availability in environmental systems. Two iron oxides (goethite and ferrihydrite) were synthesized characterized by X-ray diffraction, transmission electron microscopy and N2 adsorption method. To investigate the effect of silicon on phosphorus adsorption of them, batch equilibration method was used. Attempts were made to explore the mechanisms involved by eliminating effects of pH and accompany ions. Results reveal that the ability of two kinds of iron oxides adsorbed phosphorus were as follows: ferrihydrite > goethite. Compared with the control, silicon inhibited the adsorption of phosphorus on two iron oxides, and this effect increased with the increasing of silicon content. Langmuir, Freundlich and Temkin equations could be used to describe the adsorption characteristics of phosphorus on iron oxides well, but the Langmuir model was optimal. With silicon addition, the adsorption equilibrium constants (K) decreased of the phosphorus absorbed on iron oxide, the free energy(ΔG)dropping degree increased, the maximum adsorption capacity(Xm)and maximum buffering capacity (MBC) reduced.

scholarly journals Removal of Lead from Aqueous Solution by Adsorption using Magnesium Aluminium Hydrogenphosphate Layered Double Hydroxides

2014 ◽  
Vol 8 (1) ◽  
Author(s):  
Zaini Hamzah ◽  
Mohd Najif Ab Rahman ◽  
Yamin Yasin ◽  
Siti Mariam Sumari ◽  
Ahmad Saat
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxide ◽  
Molar Ratio ◽  
Maximum Adsorption Capacity ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Double Hydroxides

Layered double hydroxide with molar ratio of 4 (MAN 4) was synthesized by co-precipitation and followed by hydrothermal method. The compound was then later going through ion exchange with K2HPO4 for 48 hours to produce MgAlHPO4 (MAHP 4). The solid produced were characterized using X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). Adsorption of lead solution by MAHP 4 was carried out using batch experiment by mixing the lead solution and the solid of layered double hydroxide. The effects of various parameters such as contact time, pH, adsorbent dosage and initial concentration were investigated. The optimum pH for lead removal was found to be at pH of 5 and the optimum time of lead removal was found at 2 hours. The isotherm data was analysed using Langmuir and the correlation coefficient of 0.998 was obtained. The maximum adsorption capacity, Qo (mg/g) of 500 mg/g was also recorded from the Langmuir isotherm. The remaining lead solution was determined by using EDXRF (Energy Dispersive X-Ray Fluorescence spectrometry) model MiniPal 4 (PAN analytical). The results in this study indicate that MAHP 4 was an interesting adsorbent for removing lead from aqueous solution.

scholarly journals Synthesis and Characterization of CuFe2O4 Nanoparticles Modified with Polythiophene: Applications to Mercuric Ions Removal

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 586 ◽  
Author(s):  
Ayman H. Kamel ◽  
Amr A. Hassan ◽  
Abd El-Galil E. Amr ◽  
Hadeel H. El-Shalakany ◽  
Mohamed A. Al-Omar
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Transmission Electron ◽  
Enhanced Adsorption ◽  
Co Precipitation ◽  
Adsorption Desorption

In this research, CuFe2O4 nanoparticles were synthesized by co-precipitation methods and modified by coating with thiophene for removal of Hg(II) ions from aqueous solution. CuFe2O4 nanoparticles, with and without thiophene, were characterized by x-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), energy dispersive x-ray (EDX), high-resolution transmission electron microscopy (HRTEM) and Brunauer–Emmett–Teller (BET). Contact time, adsorbent dose, solution pH, adsorption kinetics, adsorption isotherm and recyclability were studied. The maximum adsorption capacity towards Hg2+ ions was 7.53 and 208.77 mg/g for CuFe2O4 and CuFe2O4@Polythiophene composite, respectively. Modification of CuFe2O4 nanoparticles with thiophene revealed an enhanced adsorption towards Hg2+ removal more than CuFe2O4 nanoparticles. The promising adsorption performance of Hg2+ ions by CuFe2O4@Polythiophene composite generates from soft acid–soft base strong interaction between sulfur group of thiophene and Hg(II) ions. Furthermore, CuFe2O4@Polythiophene composite has both high stability and reusability due to its removal efficiency, has no significant decrease after five adsorption–desorption cycles and can be easily removed from aqueous solution by external magnetic field after adsorption experiments took place. Therefore, CuFe2O4@Polythiophene composite is applicable for removal Hg(II) ions from aqueous solution and may be suitable for removal other heavy metals.

Novel Homogeneous and Mesoporous MnOx-Doped Ceria Nanosheets as Catalysts for Low-Temperature Selective Catalytic Reduction

2019 ◽  
Vol 72 (9) ◽  
pp. 657
Author(s):  
Yan Yue ◽  
Yanhua Wang ◽  
Jun Ling ◽  
Weilin Sun ◽  
Zhiquan Shen
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
Bet Surface Area ◽  
Homogeneous Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
Scr Of Nox

The development of a catalyst for the selective catalytic reduction (SCR) of NOx is essential for purifying air and the denitration of coal-burning exhaust. Herein, we prepare novel MnOx-CeO2 nanosheets with porous structures by a homogeneous coordination precipitation (HCP) method which exhibit a high NO removal efficiency above 90% in the SCR reaction at low temperature (150–240°C). The MnOx-CeO2(HCP) catalysts have a higher Brunauer–Emmett–Teller (BET) surface area and more homogeneous distribution of Mnx+ in the CeO2 lattice than those prepared by co-precipitation and precursor mixture combustion methods according to BET, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy characterizations. Together with a higher ratio of Mn4+, Ce3+, and Oα, the above properties are responsible for the high catalytic performances of MnOx-CeO2(HCP) in the SCR of NOx.

scholarly journals Experimental Design Modelling and Optimization of Triazine Herbicides Removal With Reduced Graphene Oxide Using Response Surface Method

2021 ◽  
Author(s):  
Martina Foschi ◽  
Paola Capasso ◽  
Maria Anna Maggi ◽  
Fabrizio Ruggieri ◽  
Giulia Fioravanti
Keyword(s):  
Graphene Oxide ◽  
Response Surface ◽  
Photoelectron Spectroscopy ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Pristine Graphene ◽  
X Ray Diffraction ◽  
Freundlich Model ◽  
X Ray ◽  
Reduced Graphene

Abstract In this work, triazines were chosen as the organic micropollutants model, to develop a useful method for the removal of triazine products, using a reduced derivative of graphene oxide as adsorbent material. The pristine graphene oxide and its thermally reduced derivatives under mild conditions were tested, optimizing the GO reduction conditions by means of DOE coupled with the response surface methodology. For the reduction it was decided to choose the mildest and simplest conditions possible, using an air heat treatment in a common laboratory oven. The optimal reduction conditions deduced from the response surface were calculated at a reduction temperature of 110 °C maintained for 24 hours and rGO sample was employed in the adsorption of the triazines. All the adsorbent materials have been characterized before use, by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett- Teller (BET) surface area analysis. Triazine analyses were performed by HPLC. The data obtained from the adsorption isotherms have been fitted with the Langmuir and Freundlich models, and the Freundlich model was the best one, especially for the Atraton and the Prometryn. The maximum adsorption capacity obtained was 4.4 mg/g for Atrazine, 19.4 mg/g for Atraton and 18.4 mg/g for Prometryn, at room temperature.

scholarly journals Hydrochloric Acid Modification and Lead Removal Studies on Naturally Occurring Zeolites from Nevada, New Mexico, and Arizona

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1238
Author(s):  
Garven M. Huntley ◽  
Rudy L. Luck ◽  
Michael E. Mullins ◽  
Nick K. Newberry
Keyword(s):  
New Mexico ◽  
Surface Area ◽  
Bet Surface Area ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Naturally Occurring ◽  
27Al Mas Nmr ◽  
Modified Zeolites

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

scholarly journals Photoluminescent Properties of Hydroxyapatite and Hydroxyapatite/Multi-Walled Carbon Nanotube Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Co Precipitation ◽  
Functionalized Mwcnts

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.

Sign in / Sign up

Export Citation Format

Share Document