Kinetic and thermodynamic studies of the adsorption of Cr(VI) onto some selected local adsorbents

This study presents the efficiency of bone char‐ –ZnO for eliminating chromium(VI) from aqueous solutions. The bone char‐ –ZnO composite was provided using sol‐–gel method. The elemental, morphology, surface analysis of bone char‐ –ZnO were fully studied. The prepared composite was mostly composed of Ca5(PO4)3OH and had a specific surface area of 28.09 m2/g. Results indicated that central composite design (CCD) has a desirable ability (R2 > 0.87) to predict chromium(VI) removal by bone char‐ –ZnO. Furthermore, the results suggest that the removal efficiency increased with the elevation of adsorbent dose, shaking rate, temperature, and contact time. Isotherm and kinetics investigation indicated that chromium adsorption process follows Langmuir model (R2 > 0.97 and Qm= 84.03 mg/g) and second‐ order kinetic model (R2 > 0.999). The values of ΔH° and ΔS° of the chromium adsorption reaction by bone char‐ –ZnO were obtained as 580 kJ/mol and 5.5 kJ/mol K, respectively, suggesting spontaneity and endothermicity of the reaction. Desorption study was also performed by two desorbent agents of distilled water and nitric acid. Overall, it can be concluded that the bone char‐ –ZnO composite is an efficient and potential adsorbent to be used in water and wastewater treatment plants. © 2018 American Institute of Chemical Engineers Environ Prog, 37: 1684–1695, 2018

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“…Many studies are consistent with our findings . Furthermore, in the research by Mekonnen et al , the equilibrium time was considered as 160 min.…”

Section: Resultssupporting

confidence: 91%

“…R 2 values show that entropy and enthalpy values for bone char–zinc oxide adsorbent are reliable for removal of chromium(VI). Such results have also been reported in the research by Mekonnen in adsorption of chromium(VI) .…”

Section: Resultssupporting

confidence: 85%

Chromium(VI) removal by bone char–ZnO composite: Parameters optimization by response surface methodology and modeling

Ranjbar

Hashemi

Ramavandi

et al. 2018

Env Prog and Sustain Energy

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“…Where, q e is the mass of metal adsorbed at equilibrium (mg/g), q t is the mass of metal at time t (min), K 1 the firstorder reaction rate constant of adsorption (min -1 ), and K 2 the pseudo-second-order rate constant of adsorption (mg/g).The values of K 1 and qe were calculated from the slope and intercept of the plot of log (q e -q t ) versus t while the values of K 2 and q e were evaluated from the intercept and slope of a plot of t/qt versus t, respectively (Mekonnen et al, 2015). The SEM images clearly reveal changes in the surface texture and morphology of the watermelon exposed to H 2 SO 4 .…”

Section: Adsorption Kineticsmentioning

confidence: 99%

Efficacy of Adsorption of Cu (II), Pb (II) and Cd (II) Ions onto Acid Activated Watermelon Peels Biomass from Water

2016

IJSR

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“…Therefore, the extent of water recycling and purification is expected to increase to cater for the growing demand of safe drinking water. The concentrations of metal ions in waters from underground and recycling sources may sometimes exceed the required sanitary standards [2]. Industrial wastewater is a major source of environmental water pollution and limits the use of underground water sources unless if proper water management systems are set up [3].…”

Section: Introductionmentioning

confidence: 99%

Adsorption of Lead and Copper by Carbon Black and Sodium Bentonite Composite Material: A Study on Adsorption Isotherms and Kinetics

Chiririwa¹,

Matthews²,

Nyoni³

et al. 2017

Asian J. Chem.

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The efficiency of using a composite of carbon black and sodium bentonite in treating drinking water contaminated with lead and copper ions was analyzed. The effects of pH, contact time, concentration and adsorbent dosage using an adsorbent composite of 20 % sodium bentonite and 80 % carbon black were studied. The adsorption data was analyzed with respect to Langmuir, Freundlich and Temkin isotherms. The data fits well with the Langmuir isotherm model with high coefficients of determination for both metal ions adsorption. The adsorption kinetics follows a pseudo second-order model for both metal ions. The maximum metal ion uptake (qmax) of composite adsorbent is 7.69 and 0.80 mg/g for lead and copper, respectively.

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Kinetic and thermodynamic studies of the adsorption of Cr(VI) onto some selected local adsorbents

Abstract: In this study, locally available biomasses obtained from avocado kernel seeds (AKS), Juniperus procera sawdust (JPS) and papaya peels (PP) were investigated as adsorbents for the removal of Cr (

Cited by 62 publications

References 35 publications

Chromium(VI) removal by bone char–ZnO composite: Parameters optimization by response surface methodology and modeling

Chromium(VI) removal by bone char–ZnO composite: Parameters optimization by response surface methodology and modeling

Efficacy of Adsorption of Cu (II), Pb (II) and Cd (II) Ions onto Acid Activated Watermelon Peels Biomass from Water

Adsorption of Lead and Copper by Carbon Black and Sodium Bentonite Composite Material: A Study on Adsorption Isotherms and Kinetics

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