Efficient adsorption of chlorpyrifos onto modified activated carbon by gamma irradiation; a plausible adsorption mechanism

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed S. Yahia ◽  
Ahmed S. Elzaref ◽  
Magdy B. Awad ◽  
Ahmed M. Tony ◽  
Ahmed S. Elfeky
Keyword(s):  
Gamma Irradiation ◽  
Area Measurement ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Pseudo First Order ◽  
Kinetics Of

Abstract Commercial Granulated Active Carbon (GAC) has been modified using 10 Gy dose Gamma irradiation (GAC10 Gy) for increasing its ability of air purification. Both, the raw and treated samples were applied for removing Chlorpyrifos pesticide (CPF) from ambient midair. Physicochemical properties of the two materials were characterized by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. The phase formation and microstructure were monitored using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), supported with Energy-Dispersive X-ray (EDX). The Surface area measurement was detected using BET particle size prosometry. Obtained outcomes showed that, the maximum adsorption capacity, given by Langmuir equations, was greatly increased from 172.712 to 272.480 mg/g for GAC and GAC10 Gy, respectively, with high selectivity. The overall removal efficiency of GAC10 Gy was notably comparable to that of the original GAC-sorbent. The present study indicated that, gamma irradiation could be a promising technique for treating GAC and turned it more active in eliminating the pesticides pollutants from surrounding air. The data of equilibrium has been analyzed by Langmuir and Freundlich models, that were considerably better suited for the investigated materials than other models. The process kinetics of CPF adsorbed onto both tested carbon versions were found to obey the pseudo first order at all concentrations with an exception at 70 mg/l using GAC, where, the spontaneous exothermic adsorption of Chlorpyrifos is a strong function for the pseudo-first order (PFO) and pseudo second order (PSO) kinetics.

scholarly journals Adsorption isotherm, kinetic and mechanism studies of 2-nitrophenol on sedimentary phosphate

2015 ◽  
Vol 4 (6) ◽  
pp. 289-296 ◽  
Author(s):  
Hind Yaacoubi ◽  
Zuo Songlin ◽  
Mustapha Mouflih ◽  
Mina Gourai ◽  
Said Sebti
Keyword(s):  
Kinetic Studies ◽  
Intraparticle Diffusion ◽  
X Ray Diffraction ◽  
Equilibrium Isotherms ◽  
X Ray ◽  
First Order ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
Equilibrium Adsorption Capacity

Sedimentary phosphate (SP) was used as an adsorbent for the removal of 2-nitrophenol from aqueous solutions in an attempt to investigate (the feasibility of) its application (to) in wastewater purification.  The adsorbent was characterized by X-ray diffraction (XRD), IR spectroscopy, Fluorescence X and BET.  The results indicated that the SP (was) is francolite (Ca10 (PO4,CO3)6F2) and mesoporous. The effect of the adsorption time and the pH of the solution were studied. The pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to fit adsorption data in the kinetic studies. The equilibrium isotherms were determined using the Langmuir, Freundlich and Dubinin-Radushkevich models. The results show that the Dubinin-Radushkevich isotherm had better agreement with the 2-nitrophenol adsorption on SP with a correlation coefficient of 0.98, an equilibrium adsorption capacity of 633 mg. g-1 and a corresponding contact time of 2 h. The results imply that intraparticle diffusion could be summarized as the basic rate-controlling mechanisms during 2-nitrophenol adsorption on SP.

Adsorption of polyvinyl alcohol from wastewater by sintered porous red mud

2012 ◽  
Vol 65 (11) ◽  
pp. 2055-2060 ◽  
Author(s):  
Yihe Zhang ◽  
Wei Chen ◽  
Guocheng Lv ◽  
Fengzhu Lv ◽  
Paul K. Chu ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Red Mud ◽  
Textile Wastewater ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
First Order ◽  
Pseudo Second Order ◽  
Pseudo First Order

Several types of red mud-based porous materials (RMPM) and other raw minerals via different processes were prepared and characterized using X-ray diffraction (XRD) analyses and scanning electron microscope (SEM) observations. Using the polymer sponge method, a 72% apparent porosity could be reached compared with 64% by adding a pore-forming agent. These materials were tested for their adsorption of polyvinyl alcohol (PVA) from simulated textile wastewater. The best mass ratio of RMPM to PVA solution was 50:100 with a removal maximum of 25.8% after they were in contact for 50 min. The adsorption rate and kinetics could be better described by Lagergren's pseudo-second-order model in comparison with the pseudo-first-order model.

scholarly journals Removal and Comparative Adsorption of Anionic Dye on Various MgAl synthetic Clay

2021 ◽  
Vol 11 (6) ◽  
pp. 14986-14997
Keyword(s):  
Congo Red ◽  
Adsorption Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Batch System ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Red Dye ◽  
Synthetic Clay

In this study, the adsorption of Congo red dye in an aqueous solution on two synthetic clay adsorbents, MgAl-LDH (2:1) and MgAl-LDH (3:1), was investigated using batch system experiments. The adsorbents' characterization was carried out by various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy FT-IR. The conditions applied in the adsorption experiments including the mass of adsorbent, initial concentration, contact time, pH, and temperature. The kinetic data were modeled by pseudo-first-order and pseudo-second-order. Langmuir and Freundlich's models analyzed the adsorption isotherms of Congo red on the two adsorbents. It was found that the adsorption process could be described by Langmuir isotherm. The maximum amount of adsorption is 285.71 and 166.66 mg/g for MgAl-LDH (2:1) and MgAl-LDH (3:1), respectively. Thermodynamic parameters such as enthalpy ∆H°, enthalpy ∆S°, and free enthalpy ∆G° were also evaluated to predict the nature of adsorption.

Removal of cationic and anionic dyes using purified and surfactant-modified Tunisian clays: Kinetic, isotherm, thermodynamic and adsorption-mechanism studies

Clay Minerals ◽  
2018 ◽  
Vol 53 (2) ◽  
pp. 159-174 ◽  
Author(s):  
S. Gamoudi ◽  
E. Srasra
Keyword(s):  
Aqueous Solution ◽  
Adsorption Mechanism ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Anionic Dyes ◽  
X Ray ◽  
First Order ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Influence Of Ph

ABSTRACTPurified and surfactant-modified Tunisian clays were investigated for their capacity to remove cationic and anionic dyes (crystal violet, CV and methyl orange, MO) from aqueous solution. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and potentiometric acid-base titration. Batch-sorption experiments were carried out to evaluate the influence of pH, contact time, initial dye concentration and temperature on the adsorption of dyes. Pseudo-first order, pseudo-second order, intra-particle diffusion and Elovich kinetic models were considered to evaluate the kinetic parameters. To understand the interaction of the dye with the adsorbent, Langmuir, Freundlich, Temkin and Dubinin-Radushkevish isotherms were applied. Thermodynamics studies were conducted to calculate the changes in free energy (Δ°G), enthalpy (Δ°H) and entropy (Δ°S). A difference in the maximum adsorption capacity was observed, suggesting that the retention of dyes was influenced by structure, functional groups of dyes and surface properties of the adsorbents. Moreover, different mechanisms may control the removal of dyes. The purified Tunisian clays are excellent adsorbents for removal of the cationic dye CV and its modified form is suitable for removal of the anionic dye, MO, from aqueous solution.

scholarly journals X-ray diffraction and thermodynamics kinetics of SiB6 under gamma irradiation dose

Silicon ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 2499-2504 ◽  
Author(s):  
M. N. Mirzayev ◽  
S. H. Jabarov ◽  
E. B. Asgerov ◽  
R. N. Mehdiyeva ◽  
T. T. Thabethe ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Irradiation Dose ◽  
X Ray Diffraction ◽  
X Ray ◽  
Kinetics Of

Oxidation of Nickel(II) and Manganese(II) by Peroxodisulfate in Aqueous Solution in the Presence of Molybdate. Crystal Structure of the (NH4)6[NiMo9O32].6H2O Product

1992 ◽  
Vol 45 (12) ◽  
pp. 1943 ◽  
Author(s):  
SJ Dunne ◽  
RC Burns ◽  
GA Lawrance
Keyword(s):  
Rate Constant ◽  
Linear Dependence ◽  
Ph Dependence ◽  
Order Rate Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Oxidant Concentration ◽  
Ph Range ◽  
Kinetics Of

Oxidation of Ni2+,aq, by S2O82- to nickel(IV) in the presence of molybdate ion, as in the analogous manganese system, involves the formation of the soluble heteropolymolybdate anion [MMogO32]2- (M = Ni, Mn ). The nickel(IV) product crystallized as (NH4)6 [NiMogO32].6H2O from the reaction mixture in the rhombohedra1 space group R3, a 15.922(1), c 12.406(1) � ; the structure was determined by X-ray diffraction methods, and refined to a residual of 0.025 for 1741 independent 'observed' reflections. The kinetics of the oxidation were examined at 80 C over the pH range 3.0-5.2; a linear dependence on [S2O82-] and a non-linear dependence on l/[H+] were observed. The influence of variation of the Ni/Mo ratio between 1:10 and 1:25 on the observed rate constant was very small at pH 4.5, a result supporting the view that the precursor exists as the known [NiMo6O24H6]4- or a close analogue in solution. The pH dependence of the observed rate constant at a fixed oxidant concentration (0.025 mol dm-3) fits dequately to the expression kobs = kH [H+]/(Ka+[H+]) where kH = 0.0013 dm3 mol-1 s-1 and Ka = 4-0x10-5. The first-order dependence on peroxodisulfate subsequently yields a second-order rate constant of 0.042 dm3 mol-1 s-1. Under analogous conditions, oxidation of manganese(II) occurs eightfold more slowly than oxidation of nickel(II), whereas oxidation of manganese(II) by peroxomonosulfuric acid is 16-fold faster than oxidation by peroxodisulfate under similar conditions.

scholarly journals Adsorption purification of waste water from chromium by ferrite manganese

2020 ◽  
Vol 168 ◽  
pp. 00026
Author(s):  
Liliia Frolova ◽  
Mykola Kharytonov ◽  
Iryna Klimkina ◽  
Oleksandr Kovrov ◽  
Andrii Koveria
Keyword(s):  
Adsorption Process ◽  
Uv Spectroscopy ◽  
Second Order ◽  
Waste Waters ◽  
Equilibrium Isotherms ◽  
X Ray ◽  
First Order ◽  
Freundlich Isotherms ◽  
Pseudo Second Order ◽  
Kinetics Of

Plasma method is used to synthesize manganese ferrite. The basic properties of ferrite are determined by IR spectroscopy, UV spectroscopy, X-ray phase analysis, vibration magnetometry. The paper shows that the use of magnetically controlled sorbent allows to purify waste waters from chromium (III). The process of adsorption of chromium cations (III) is investigated. The kinetics of the process is studied. To describe the equilibrium isotherms, the experimental data are analysed by the models of Langmuir, Freundlich isotherms. Pseudo-first order, pseudo-second-order, and Weber-Morris are used to elucidate the kinetic parameters and mechanism of the adsorption process. It has been established that the removal of Cr (III) cations is described by the pseudo-second order of the Langmuir reaction and mechanism.

scholarly journals Synthesis Fe3O4/Talc nanocomposite by coprecipition-ultrasonication method and advances in hexavalent chromium removal from aqueous solution

2020 ◽  
Vol 38 (9-10) ◽  
pp. 483-501
Author(s):  
Nguyen Thi Huong ◽  
Nguyen Ngoc Son ◽  
Vo Hoang Phuong ◽  
Cong Tien Dung ◽  
Pham Thi Mai Huong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Batch Experiments ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Langmuir And Freundlich Equations

The Fe3O4/Talc nanocomposite was synthesized by the coprecipitation-ultrasonication method. The reaction was carried out under a inert gas environment. The nanoparticles were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry techniques (VSM), the surface area of the nanoparticles was determined to be 77.92 m2/g by Brunauer-Emmett-Teller method (BET). The kinetic data showed that the adsorption process fitted with the pseudo-second order model. Batch experiments were carried out to determine the adsorption kinetics and mechanisms of Cr(VI) by Fe3O4/Talc nanocomposite. The adsorption process was found to be highly pH-dependent, which made the material selectively adsorb these metals from aqueous solution. The isotherms of adsorption were also studied using Langmuir and Freundlich equations in linear forms. It is found that the Langmuir equation showed better linear correlation with the experimental data than the Freundlich. The thermodynamics of Cr(VI) adsorption onto the Fe3O4/Talc nanocomposite indicated that the adsorption was exothermic. The reusability study has proven that Fe3O4/Talc nanocomposite can be employed as a low-cost and easy to separate.

Beobachtungen von Stapelfehlordnungen bei der Oxydation der zweiten zur ersten Stufe des Graphithydrogensulfats / Observation of stacking disorder during the oxidation of second stage to first stage graphite hydrogensulfate

1984 ◽  
Vol 39 (8) ◽  
pp. 768-777 ◽  
Author(s):  
Ko Young Shin ◽  
Hanns-Peter Boehm
Keyword(s):  
Interlayer Spacing ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Second Stage ◽  
Intermediate Phases ◽  
Degree Of Oxidation ◽  
Stage 1 ◽  
Kinetics Of ◽  
Stacking Disorder

Graphite has been oxidized to graphite hydrogensulfate with (NH4)2S2Og in concentrated H2SO4. The stage 2 compound formed very rapidly, but further oxidation to stage 1 could be followed conveniently. X-ray diffraction of the intermediate phases showed nonintegral (00l)-reflections indicative of partial interstratification disorder. The interlayer spacing of the stage 1 compound increased with continued oxidation. The degree of oxidation as function of oxidation time has been determined from the position of the minima in the reflectance spectra. The density of the compounds and the ratio of acid molecules to anions in the intercalated layers has been estimated using these data and those of buoyancy measurements. There is a minimum in packing density early in the formation of the first stage. The kinetics of intercalation seems to be first order with respect to the free interlayer spaces.

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