Sorption of Rhodamine B Dye onto Bentonite Clay-silane Composite Materials

2021 ◽  
Vol 9 (2) ◽  
pp. 161-168
Author(s):  
Ralte Malsawmdawngzela ◽  
◽  
Thanhming liana ◽  
Diwakar Tiwari ◽  
◽  
...  

The aim of this communication is to assess the sorption behavior of silanes grafted bentonite composite materials for Rhodamine B (RhB) from aqueous solution. The nanocomposites were synthesized by functionalization of the bentonite with 3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane under inert atmosphere. The batch experimental data indicated that the composite materials showed high percentage removal of RhB over a wide pH range, i.e., pH ~4.0 to 10.0. A high percentage removal of RhB was achieved within the concentrations studied from 1.0 to 25.0 mgL-1. Langmuir and Freundlich adsorption isotherm were obtained using equilibrium state sorption data. The equilibrium sorption was attained within 180 min of contact and the kinetic model best fitted the pseudo-second-order model. Further, the change in background electrolyte (NaCl) concentrations from 0.0001 to 0.1molL-1 NaCl and the presence of co-existing ions do not significantly affect the sorption of RhB by the composite sorbents except for EDTA.

2016 ◽  
Vol 4 (2) ◽  
pp. 105-112
Author(s):  
Lalchhing puii ◽  
◽  
Seung-Mok Lee ◽  
Diwakar Tiwari ◽  
◽  
...  

A mesoporous silica was synthesized by annealing (3-Aminopropyl) triethoxysilane grafted chitosan at 800˚C. The mesoporous silica was characterized by the XRD (X-ray diffraction) analysis. The BET specific surface area and pore size of silica was found to be 178.42 m2/g and 4.13 nm. The mesoporous silica was then employed for the efficient remediation of aqueous solutions contaminated with Cu(II) under batch and column reactor operations. The mesoporous silica showed extremely high per cent removal of Cu(II) at wide pH range i.e., pH ~2.0 to 7.0. Relatively a fast uptake of Cu(II) was occurred and high percentage removal was obtained at initial concentrations studied from 1.0 to 15.0 mg/L. The equilibrium state sorption data were utilized for the Langmuir and Freundlich adsorption isotherm studies. Moreover, the effect of an increase in background electrolyte concentrations from 0.0001 to 0.1 mol/L NaNO3 was assessed for the uptake of Cu(II) by mesoporous silica. The equilibrium sorption was achieved within 240 min of contact and the kinetic data is best fitted to the pseudo-second-order and fractal like pseudo-second-order kinetic models. In addition, the mesoporous silica was used for dynamic studies under column reactor operations. The breakthrough curve was then used for the non-linear fitting of the Thomas equation and the loading capacity of the column for Cu(II) was estimated.


2021 ◽  
Vol 9 (2) ◽  
pp. 54-64
Author(s):  
Lalmalsawm dawngliani ◽  
◽  
Gospel Lallawmzuali ◽  
Samuel Lallianrawna ◽  
Thanhming liana ◽  
...  

IMO compost was obtained using Indigenous Microorganisms (IMO) as inoculant through anaerobic fermentation process from kitchen waste biomass. The Physico-chemical analysis of the solid was obtained by taking pH, MC, OM, OC, N, K and P content. The biosorbent material was further characterized by SEM, IR and BET analytical techniques. Various physico-chemical parametric studies viz. effect of pH, initial dye concentration and background electrolyte concentrations are performed in the removal of Congo red (CR) dye using the IMO compost. The lower pH condition pH < 6.0 favoured the removal of Congo red and the percent removal was decreased with increase in the CR concentration. The removal of Congo red followed the pseudo-second order rate kinetics and the equilibrium state sorption data was reasonably fitted well to the Freundlich adsorption isotherm. In addition, the minimal effect of background electrolyte concentrations (0.0001 to 0.1 mol/L NaNO3) in the removal of CR inferred a specific sorption of Congo red forming ‘inner sphere’ complexes at the surface of the biosorbent.


2015 ◽  
Vol 12 (1) ◽  
pp. 148-156
Author(s):  
Baghdad Science Journal

The subject of this research involves studying adsorption to removal herbicide Atlantis WG from aqueous solutions by bentonite clay. The equilibrium concentration have been determined spectra photometry by using UV-Vis spectrophotometer. The experimental equilibrium sorption data were analyzed by two widely, Langmuir and Freundlish isotherm models. The Langmuir model gave a better fit than Freundlich model The adsorption amount of (Atlantis WG) increased when the temperature and pH decreased. The thermodynamic parameters like ?G, ?H, and ?S have been calculated from the effect of temperature on adsorption process, is exothermic. The kinetic of adsorption process was studied depending on Lagergren ,Morris ? Weber and Rauschenberg equations.


2010 ◽  
Vol 7 (1) ◽  
pp. 745-756
Author(s):  
Baghdad Science Journal

The subject of this research involves studying adsorption to remove hexavalent chromium Cr(VI) from aqueous solutions. Adsorption process on bentonite clay as adsorbent was used in the Cr(VI) concentration range (10-100) ppm at different temperatures (298, 303, 308 and 313)K, for different periods of time. The adsorption isotherms were obtained by obeying Langmuir and Freundlich adsorption isotherm with R2 (0.9921-0.9060) and (0.994-0.9998), respectively. The thermodynamic parameters were calculated by using the adsorption process at four different temperatures the values of ?H, ?G and ?S was [(+6.582 ? +6.547) kJ.mol-1, (-284.560 ? -343.070) kJ.mol-1 and (+0.977 ? +1.117) kJ.K-1.mol-1] respectively. This data indicates the spontaneous sorption process. The kinetic study of adsorption process was studied depending on three kinetic equations: 1- Lagergren equation 2- Morris-Weber equation 3- Reichenberg equation


2002 ◽  
Vol 757 ◽  
Author(s):  
Yngve Albinsson ◽  
Arvid Ödegaard-Jensen ◽  
Virginia M. Oversby ◽  
Lars O. Werme

ABSTRACTSweden plans to dispose of spent nuclear fuel in a deep geologic repository in granitic rock. The disposal conditions allow water to contact the canisters by diffusion through the surrounding bentonite clay layer. Corrosion of the canister iron insert will consume oxygen and provide actively reducing conditions in the fluid phase. Experiments with spent fuel have been done to determine the dissolution behavior of the fuel matrix and associated fission products and actinides under conditions ranging from inert atmosphere to reducing conditions in solutions. Data for U, Pu, Np, Cs, Sr, Tc, Mo, and Ru have been obtained for dissolution in a dilute NaHCO3 groundwater for 3 conditions: Ar atmosphere, H2 atmosphere, and H2 atmosphere with Fe(II) in solution. Solution concentrations forU, Pu, and Mo are all significantly lower for the conditions that include Fe(II) ions in the solutions together with H2 atmosphere, while concentrations of the other elements seem to be unaffected by the change of atmospheres or presence of Fe(II). Most of the material that initially dissolved from the fuel has reprecipitated back onto the fuel surface. Very little material was recovered from rinsing and acid stripping of the reaction vessels.


2019 ◽  
Vol 9 (5) ◽  
pp. 51-55
Author(s):  
Vijayalakshmi G ◽  
B. Ramkumar

The present work reported the adsorption of Cr (VI) from aqueous solutions on activated carbon prepared from teak wood waste. Biomass from teak wood were taken out and pulverized in a micro-pulverizing mill. The powder thus obtained was activated with 40% H3PO4 and carbonized at 600 °C for 1 hour in an inert atmosphere. Physico-chemical characteristics such as  functional groups and surface morphology of the activated carbon were analyzed using FTIR spectroscopy and SEM analysis respectively. Batch adsorption experiments were performed to investigate the effects of Cr (VI) concentration, carbon dose, pH and time. The maximum adsorption capacity of Cr(VI) was found to be 1.5 g/L at pH 3 and temperature 30±1 °C. The Freundlich adsorption isotherm best represented the equilibrium data and a pseudo-second order relation represented the adsorption kinetics.


Author(s):  
A. K. Vetcher ◽  
G. A. Govor ◽  
K. I. Yanushkevich ◽  
U. T. Berdiev ◽  
F. F. Khasanov

The influence of synthesis conditions on the magnetic characteristics of composite materials based on iron powders ASC 100.29 (Sweden) and LiaoNing (China) is investigated. The surface of metallic iron powders is encapsulated by an insulating ferrite coating, consisting of iron oxides and phosphides. The synthesis was carried out at a temperature of 150 °C from a gaseous medium in a special reactor at a pressure of 1 atm. Insulating oxide coatings were applied both to the initial iron powder without treatment, and to previously annealed powders in an inert atmosphere and in a mixture of hydrogen-argon. To conduct studies of magnetic characteristics, cores in the form of rings were made by pressing method. The dependence of induction vs. magnitude of the magnetic field, magnetization reversal losses (hysteresis losses) in the full and in the private loop were recorded by an express magnetometer. The value of losses was calculated by the hysteresis loops area. The results show that composite low-frequency magnetic materials based on metallic iron ASC 100.29 and LiaoNing powders have similar values of magnetic parameters – almost identical B = f(H) dependencies, but the magnetization reversal losses for ASC 100.29 are significantly lower than for LiaoNing powder under equal insulating coatings synthesis conditions. It is possible to use such materials as magnetic cores in various electrical devices, such as cores of high-frequency transformers and a number of electrical machines. Since such materials can operate at frequencies from 1 kHz and higher, this will significantly reduce the overall dimensions and increase the efficiency of electrical products.


Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 59
Author(s):  
Alexey V. Shapagin ◽  
Natalia A. Gladkikh ◽  
Arkadiy A. Poteryaev ◽  
Valentina Yu. Stepanenko ◽  
Uliana V. Nikulova ◽  
...  

The development of universal finishing compositions for fibers of various natures is an urgent task for polymer composite materials science. The developed finishes can be used for the fiber reinforcement of polymer matrices with a wide range of surface free energy characteristics. Epoxy systems modified with diaminesilane in a wide concentration range were examined by optical interferometry, FTIR spectroscopy, DSC and the sessile drop technique. It was shown that the partial curing of epoxy resin by diaminesilane at room temperature under an inert atmosphere, followed by contact with air, leads to a significant increase of the surface free energy of the system. Varying the concentration of diaminesilane allows us to effectively regulate the surface free energy of the composition. This makes it possible to use fibers finished with epoxyaminosilane compositions in composite materials based on a various thermosetting and thermoplastic binders with a surface tension of up to 75 mJ/m2.


Author(s):  
A. Salihu ◽  
E.D. Audu ◽  
P. Nzerem ◽  
S.B. Gimba ◽  
I. Okafor ◽  
...  

Curtailing the effects of environmental pollution being a major problem encountered by third-world countries, this study was embarked on to reduce the effect of land and water pollution caused by improper disposal of dye used by industries by using readily available agricultural waste like peanut Shell, bentonite clay and its composite. Analysis that was used included Scanning electron microscope (SEM), Electron dispersive x-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) Some physical parameters were considered too: Absorbent load, Contact time, pH and Concentration. The results from the SEM, EDX and FTIR showed the adsorptive capacities of the absorbents, it’s functional and the compounds contained. The result of the physical parameters for adsorbent load; Peanut shell the percentage removal increase from 26.93%-28.0% .For bentonite clay increase from 7.05%-8.24%. The combination of both peanut shell and bentonite increased from 93.22%-95.40%. For the contact time the dye removal percentage increase from 99.13%-99.37% which later decreased to 98.16%.Bentonite clay decreased from 71.09%-69.53% and later increased to 70.13%. The combination decreased from 52.33%-51.29% and increased to 52.60%bbut decreased at the last lap to 50.83% At 60-80minutes optimal time was achieved due to saturation of active sites for high removal of dye efficiency. pH was observed too which varied. Peanut shell shows that the percentage removal increased from 61.89%-62.37% then decreased to 60.87%.Bentonite clay decreased from completely from 99.72%-97.58%. The combination decreased from 32.14%-31.94% then increased to 33.54%.We can say that for the peanut shell and the combination of both peanut shell and bentonite clay pH was increased slightly at the acidic side.


2017 ◽  
Vol 77 (3) ◽  
pp. 638-646 ◽  
Author(s):  
Neonjyoti Bordoloi ◽  
Manash Deep Dey ◽  
Rupak Mukhopadhyay ◽  
Rupam Kataki

Abstract Biochar obtained through the pyrolysis of Pongamia glabra seed cover (PGSC) at 550 °C with a heating rate of 40 °C/min was characterized and its ability to adsorb the dyes Methylene blue (MB) and Rhodamine B (RB) from aqueous solutions was investigated. The effect of pH, temperature and initial concentration of the dyes on adsorption behavior were investigated. The equilibrium sorption data were analyzed by using Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D-R) isotherms. Equilibrium data were well fitted for D-R isotherm in case of MB and Langmuir isotherm in case of RB dyes. The kinetics of dye adsorption on PGSC biochar was well described by applying pseudo-second-order rate equations. The surface of adsorbent before and after the removal of dyes was characterized by using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis. The study suggested that PGSC biochar could be used as a highly efficient adsorbent for the removal of synthetic dyes.


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