scholarly journals Arsenic Removal from Aqueous Solutions Using Carbon Embedded Silica and Zeolite: Column Adsorption Studies

2020 ◽  
pp. 42-53
Keyword(s):  
Aqueous Solutions ◽  
Rice Husk ◽  
Arsenic Removal ◽  
Freundlich Isotherm ◽  
Column Height ◽  
Isotherm Models ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Column Adsorption

Column adsorption of the As (III) & As (V) using rice husk mediated carbon embedded silica (CES) and zeolite (Z-RHA) has been proved promising technique rather than the other conventional methods. The present work investigates the adsorption capability of newly manufactured CES and Z-RHA to remove As (III) & As (V) from aqueous solutions. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive X-ray (EDX), and Transmission electron microscopy (TEM) analysis have been investigated for the characterization of synthesized materials. The effects of different parameters like initial concentrations, column diameter, column height, particle size distribution have been investigated. The maximum removal efficiency of CES adsorbents for As (III) is 98% and for As (V) is 85%, and of Z-RHA for As (III) is 95% and for As (V) is 92%. To describe the adsorption behavior the Langmuir and Freundlich isotherm models as well as to kinetics models like Adam-Bohart, Thomas, and Yoon Nelson model were applied. Finally, to dispose of the rice husk mediated adsorbents after arsenic treatment solidification has been done.

scholarly journals Arsenic Removal from Aqueous Solutions bySalvadora persicaStem Ash

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ferdos Kord Mostafapour ◽  
Edris Bazrafshan ◽  
Mahdi Farzadkia ◽  
Samira Amini
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Arsenic Removal ◽  
Arsenic Concentration ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Aqueous Environment ◽  
Salvadora Persica ◽  
Naturally Occurring ◽  
Maximum Removal

Arsenic is a naturally occurring metalloid, which is widely distributed in nature and is regarded as the largest mass poisoning in history. In the present study, the adsorption potential ofSalvadora persica(S. persica) stem ash in a batch system for the removal of As(V) from aqueous solutions was investigated. Isotherm studies were carried out to evaluate the effect of contact time (20–240 min), pH (2–11), initial arsenic concentration (50–500 μg/L), and adsorbent dose on sorption efficiency. Maximum removal efficiency of 98.33% and 99.32% was obtained at pH 6, adsorbent dosage 3.5 g/L, initial As(V) concentration 500 μg/L, and contact time 80 and 60 min forS. persicastem ash at 300 °C and 500 °C, respectively. Also, the adsorption equilibriums were analyzed by the Langmuir and Freundlich isotherm models. Such equilibriums showed that the adsorption data was well fitted with the Freundlich isotherm model forS. persicastem ash at both 300 °C and 500 °C (R2=0.8983and 0.9274, resp.). According to achieved results, it was defined thatS. persicastem ash can be used effectively for As(V) removal from the aqueous environment.

scholarly journals Reuse of Brick Waste as a Cheap-Sorbent for the Removal of Nickel Ions from Aqueous Solutions

2020 ◽  
Vol 21 (2) ◽  
pp. 15-23
Author(s):  
Teba Hameed Mhawesh ◽  
Ziad T. Abd Ali
Keyword(s):  
Aqueous Solutions ◽  
Freundlich Isotherm ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Sorption Data ◽  
Nickel Ions ◽  
X Ray ◽  
First Order ◽  
Pseudo First Order

   The potential application of granules of brick waste (GBW) as a low-cost sorbent for removal of Ni+2ions from aqueous solutions has been studied. The properties of GBW were determined through several tests such as X-Ray diffraction (XRD), Energy dispersive X-ray (EDX), Scanning electron microscopy (SEM), and BET surface area. In batch tests, the influence of several operating parameters including contact time, initial concentration, agitation speed, and the dose of GBW was investigated. The best values of these parameters that provided maximum removal efficiency of nickel (39.4%) were 1.5 hr, 50 mg/L, 250 rpm, and 1.8 g/100mL, respectively. The adsorption data obtained by batch experiments subjected to the Three isotherm models called Langmuir, Freundlich and Elovich, The results showed that the Freundlich isotherm model described well the sorption data (R2=0.9176) in comparison with other models. The kinetic data were analyzed using two kinetic models called pseudo-first-order and pseudo-second-order. The pseudo-first-order kinetic model was found to agree well with the experimental data.  

Effectiveness of Calcium Deficiency in Nanosized Hydroxyapatite for Removal of Fe(II), Cu(II), Ni(II) and Cr(VI) Ions from Aqueous Solutions

2019 ◽  
Vol 56 ◽  
pp. 17-27
Author(s):  
Van Dat Doan ◽  
Van Thuan Le ◽  
Hoang Sinh Le ◽  
Dinh Hien Ta ◽  
Hoai Thuong Nguyen
Keyword(s):  
Electron Microscopy ◽  
Ion Exchange ◽  
Aqueous Solutions ◽  
Calcium Deficiency ◽  
Exchange Mechanism ◽  
Precipitation Method ◽  
X Ray ◽  
Transmission Electron ◽  
Bet Method ◽  
Langmuir Isotherm Model

In this work, nanosized calcium deficient hydroxyapatite (nCDHA) was synthesized by the precipitation method, and then utilized as an adsorbent for removal of Fe (II), Cu (II), Ni (II) and Cr (VI) ions from aqueous solutions after characterizing it by various techniques as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and BET method. A possible structure of synthesized nCDHA was proposed. The adsorption study indicated that the adsorption equilibrium is well fitted with Langmuir isotherm model with the maximum adsorption capacities followed the order of Fe (II) > Cu (II) > Ni (II) > Cr (VI) with the values of 137.23, 128.02, 83.19 and 2.92 mg/g, respectively. The ion-exchange mechanism was dominant for the adsorption of metal ions onto nCDHA at initial metal concentrations lower than 0.01 mol/L. Along with the ion-exchange mechanism, there was an additional precipitation occurred on the surface of nCDHA in the case of Fe (II) and Cu (II) at initial concentrations higher than 0.01 mol/L.

scholarly journals Multi-Component Adsorption of Benzene, Toluene, Ethylbenzene, and Xylene from Aqueous Solutions by Montmorillonite Modified with Tetradecyl Trimethyl Ammonium Bromide

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
H. Nourmoradi ◽  
Mehdi Khiadani ◽  
M. Nikaeen
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Structural Changes ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Ammonium Bromide ◽  
Order Kinetic ◽  
Multicomponent Adsorption ◽  
Benzene Toluene ◽  
Kinetic And Isotherm Models

Multicomponent adsorption of benzene, toluene, ethylbenzene, and xylene (BTEX) was assessed in aqueous solutions by montmorillonite modified with tetradecyl trimethyl ammonium bromide (TTAB-Mt). Batch experiments were conducted to determine the influences of parameters including loading rates of surfactant, contact time, pH, adsorbate concentration, and temperature on the adsorption efficiency. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to determine the adsorbent properties. Results showed that the modification of the adsorbent via the surfactant causes structural changes of the adsorbent. It was found that the optimum adsorption condition achieves with the surfactant loading rate of 200% of the cation exchange capacity (CEC) of the adsorbent for a period of 24 h. The sorption of BTEX by TTAB-Mt was in the order ofB<T<E<X. The experimental data were fitted by many kinetic and isotherm models. The results also showed that the pseudo-second-order kinetic model and Freundlich isotherm model could, respectively, be fitted to the experimental data better than other available kinetic and isotherm models. The thermodynamic study indicated that the sorption of BTEX with TTAB-Mt was achieved spontaneously and the adsorption process was endothermic as well as physical in nature. The regeneration results of the adsorbent also showed that the adsorption capacity of adsorbent after one use was 51% to 70% of original TTAB-Mt.

scholarly journals The role of Arthrobacter viscosus in the removal of Pb(II) from aqueous solutions

2017 ◽  
Vol 76 (7) ◽  
pp. 1726-1738 ◽  
Author(s):  
Raluca Maria Hlihor ◽  
Mihaela Roşca ◽  
Teresa Tavares ◽  
Maria Gavrilescu
Keyword(s):  
Aqueous Solutions ◽  
Isotherm Models ◽  
X Ray ◽  
Optimum Parameters ◽  
Living Biomass ◽  
Initial Ph ◽  
Edx Analyses ◽  
Arthrobacter Viscosus ◽  
Kinetic And Isotherm Models

The aim of this paper was to establish the optimum parameters for the biosorption of Pb(II) by dead and living Arthrobacter viscosus biomass from aqueous solution. It was found that at an initial pH of 4 and 26 °C, the dead biomass was able to remove 97% of 100 mg/L Pb(II), while the living biomass removed 96% of 100 mg/L Pb(II) at an initial pH of 6 and 28 ± 2 °C. The results were modeled using various kinetic and isotherm models so as to find out the mechanism of Pb(II) removal by A. viscosus. The modeling results indicated that Pb(II) biosorption by A. viscosus was based on a chemical reaction and that sorption occurred at the functional groups on the surface of the biomass. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX) analyses confirmed these findings. The suitability of living biomass as biosorbent in the form of a biofilm immobilized on star-shaped polyethylene supports was also demonstrated. The results suggest that the use of dead and living A. viscosus for the removal of Pb(II) from aqueous solutions is an effective alternative, considering that up to now it has only been used in the form of biofilms supported on different zeolites.

scholarly journals Characterization of glycidyl methacrylate based magnetic nanocomposites

2019 ◽  
Vol 73 (1) ◽  
pp. 25-35
Author(s):  
Bojana Markovic ◽  
Vojislav Spasojevic ◽  
Aleksandra Dapcevic ◽  
Zorica Vukovic ◽  
Vladimir Pavlovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Nanoparticles ◽  
Glycidyl Methacrylate ◽  
Mercury Porosimetry ◽  
Magnetic Nanocomposite ◽  
Magnetic Nanocomposites ◽  
Tem Analysis ◽  
X Ray ◽  
Force Microscopy ◽  
Transmission Electron

Magnetic and non-magnetic macroporous crosslinked copolymers of glycidyl methacrylate and trimethylolpropane trimethacrylate were prepared by suspension copolymerization and functionalized with diethylenetriamine. The samples were characterized by mercury porosimetry, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy analysis (FTIR-ATR), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM) and SQUID magnetometry. The FTIR-ATR analysis of synthesized magnetic nanocomposites confirmed the presence of magnetite and successful amino- functionalization. Non-functionalized and amino-functionalized nanocomposites exhibited superparamagnetic behavior at 300 K, with a saturation magnetization of 5.0 emu/g and 2.9 emu/g, respectively. TEM analysis of the magnetic nanocomposite has shown that magnetic nanoparticles were homogeneously dispersed in the polymer matrix. It was demonstrated that incorporation of magnetic nanoparticles enhanced the thermal stability of the magnetic nanocomposite in comparison to the initial non-magnetic macroporous copolymer.

scholarly journals Removal of Hexavalent Chromium Ions from Aqueous Solutions by an Anion-Exchange Resin

2008 ◽  
Vol 26 (9) ◽  
pp. 693-703 ◽  
Author(s):  
P. Senthil Kumar ◽  
K. Kirthika ◽  
K. Sathish Kumar
Keyword(s):  
Aqueous Solutions ◽  
Anion Exchange ◽  
Hexavalent Chromium ◽  
Exchange Resin ◽  
Ph Value ◽  
Anion Exchange Resin ◽  
Freundlich Isotherm ◽  
Sorption Process ◽  
Isotherm Models ◽  
Exchange Resins

The removal of hexavalent chromium, Cr(VI), from aqueous solutions under different conditions using an anion-exchange resin (AXR) as an adsorbent was investigated under batch conditions. Such studies indicated that the percentage adsorption decreased with increasing initial Cr(VI) concentration, with the maximum removal of such ions occurred at a pH value of ca. 2.0. Both the Langmuir and Freundlich isotherm models were capable of reproducing the isotherms obtained experimentally. The sorption process was rapid during the first 20 min with equilibrium being attained within 30 min. The process followed first-order kinetics. The results demonstrate that such anion-exchange resins can be used for the efficient removal of Cr(VI) ions from water and wastewater.

scholarly journals Surface Study of CuO Nanopetals by Advanced Nanocharacterization Techniques with Enhanced Optical and Catalytic Properties

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1298 ◽  
Author(s):  
Muhammad Arif Khan ◽  
Nafarizal Nayan ◽  
Shadiullah Shadiullah ◽  
Mohd Khairul Ahmad ◽  
Chin Fhong Soon
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
Average Length ◽  
Tem Analysis ◽  
X Ray ◽  
Surface Study ◽  
Transmission Electron ◽  
One Step ◽  
Controlled Morphology ◽  
Xrd Patterns

In the present work, a facile one-step hydrothermal synthesis of well-defined stabilized CuO nanopetals and its surface study by advanced nanocharacterization techniques for enhanced optical and catalytic properties has been investigated. Characterization by Transmission electron microscopy (TEM) analysis confirmed existence of high crystalline CuO nanopetals with average length and diameter of 1611.96 nm and 650.50 nm, respectively. The nanopetals are monodispersed with a large surface area, controlled morphology, and demonstrate the nanocrystalline nature with a monoclinic structure. The phase purity of the as-synthesized sample was confirmed by Raman spectroscopy and X-ray diffraction (XRD) patterns. A significantly wide absorption up to 800 nm and increased band gap were observed in CuO nanopetals. The valance band (VB) and conduction band (CB) positions at CuO surface are measured to be of +0.7 and −1.03 eV, respectively, using X-ray photoelectron spectroscopy (XPS), which would be very promising for efficient catalytic properties. Furthermore, the obtained CuO nanopetals in the presence of hydrogen peroxide ( H 2 O 2 ) achieved excellent catalytic activities for degradation of methylene blue (MB) under dark, with degradation rate > 99% after 90 min, which is significantly higher than reported in the literature. The enhanced catalytic activity was referred to the controlled morphology of monodispersed CuO nanopetals, co-operative role of H 2 O 2 and energy band structure. This work contributes to a new approach for extensive application opportunities in environmental improvement.

scholarly journals The Removal of Uranium and Thorium from Their Aqueous Solutions by 8-Hydroxyquinoline Immobilized Bentonite

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Salah ◽  
Gaber ◽  
Kandil
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Langmuir Isotherm ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.

Analysis of the Intermetallic Compound Formed in Hot Dip Aluminized Steel

2006 ◽  
Vol 15-17 ◽  
pp. 159-163 ◽  
Author(s):  
Kee Hyun Kim ◽  
Benny van Daele ◽  
Gustaaf Van Tendeloo ◽  
Yong Sug Chung ◽  
Jong Kyu Yoon
Keyword(s):  
Intermetallic Compound ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Liquid Aluminium ◽  
Thin Specimen ◽  
Tem Analysis ◽  
X Ray ◽  
Cell Parameters ◽  
Transmission Electron ◽  
Aluminized Steel

A hot dip aluminising process was carried out with a 1mm steel sheet dipped into the Al-10at.% Si melt in an automatic hot-dip simulator. When steel and liquid aluminium are in contact with each other, a thin intermetallic compound (IMC) is formed between the steel and the aluminium. The analysis and identification of the formation mechanism of the IMC is needed to manufacture the application products. Energy dispersive X-ray spectroscopy (EDX) and electron probe microanalysis (EPMA) are normally used to identify the phases of IMC. In the Al-Fe-Si system, numerous compounds with only slight differences in composition are formed. Consequently, EDX and EPMA are insufficient to confirm exactly the thin IMC with multiphases. In this study, transmission electron microscopy (TEM) analysis combined with EDX was used. The TEM sample was prepared with focused ion beam (FIB) sampling. The FIB lift-out technology is used to slice a very thin specimen with minimum contamination for TEM analysis. It is clearly shown that the IMC consists of Al-27 at. % Fe-10 at. % Si and is identified as Al8Fe2Si with a hexagonal unit cell (space group P63/mmc). The cell parameters are a= 1.2404nm and c= 2.6234nm.

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