Evaluation of Chitosan Modified by Sodium Dodecyl Sulfate for Removing Hexavalent Chromium from Aqueous Solutions

2020 ◽  
pp. 13-22
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Aqueous Solutions ◽  
Hexavalent Chromium ◽  
Sodium Dodecyl ◽  
Second Order ◽  
Order Kinetic ◽  
Batch Mode ◽  
Dodecyl Sulfate ◽  
Pseudo Second Order ◽  
Langmuir And Freundlich Models

Hexavalent chromium (Cr(VI)) has the characteristic of forming anionic species, which are very toxic, very soluble in water and difficult to be removed. In this study, dichromate removal from aqueous solutions by chitosan and chitosan modified by sodium dodecyl sulfate (SDS) was addressed. The effect of various experimental parameters, such as pH (1-9), initial concentration (10-100 mg L-1), adsorbent dose (0.005-0.350 g) and contact time (5-60 min) was investigated. All experiments were conducted in batch mode at room temperature (~21 oC). The obtained equilibrium adsorption isotherms were analyzed using the Langmuir and Freundlich models. Furthermore, the kinetics of dichromate removal was analyzed by pseudo-first order, pseudo-second order and the Elovich models. Optimum conditions for obtaining high removal (~97%) within a relatively short time (60 min) are: 5.0 pH, 0.100 g SDS-chitosan dosage and an initial Cr2O72- concentration of 10 mg L-1. The dichromate adsorption capacity of chitosan is 8.3 mg L-1, while that of SDS-chitosan is 9.7 mg L-1. In addition, the adsorption of dichromate by chitosan and SDS-chitosan is well-fitted by the Langmuir and Freundlich models while the adsorption kinetics is best fitted by the pseudo-second-order kinetic model.

scholarly journals Removing of Hexavalent Chromium from Aqueous Solutions Using Dried Yogurt, and Studying Isotherm, Kinetic and Thermodynamic Parameters

2019 ◽  
Vol 16 (3) ◽  
pp. 0603
Author(s):  
Sultan Et al.
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Hexavalent Chromium ◽  
Treatment Time ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Order Kinetic ◽  
Kinetic And Thermodynamic Parameters ◽  
Pseudo Second Order ◽  
Adsorbent Treatment

     In this study, Yogurt was dried and milled, then shaked with distilled water to remove the soluble materials, then again dried and milled. Batch experiments were carried out to remove hexavalent chromium from aqueous solutions. Different parameters were optimized such as amount of adsorbent, treatment time, pH and concentration of adsorbate. The concentrations of Cr6+ in solutions are determined by UV-Visible spectrophotometer.  Maximum percentage removal of Cr6+ was 82% at pH 2. Two equilibrium adsorption isotherms mechanisms are tested Langmuir and Freundlich, the results showed that the isotherm obeyed to Freundlich isotherm. Kinetic models were applied to the adsorption of Cr6+ ions on the adsorbents, pseudo-first-order, the pseudo second-order respectively. Results showed that pseudo second-order kinetic model was applicable to the experimental data well. The thermodynamic parameters such as ΔGº, ΔHº and ΔSº were calculated. ∆H°, ∆S° and ΔGº for this study were negative indicating that the process is exothermic, while negative values of ΔGº indicate spontaneous process.

scholarly journals Removal of Methylene Blue from Aqueous Solution by Activated Carbon Prepared from Pea Shells (Pisum sativum)

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ünal Geçgel ◽  
Gülce Özcan ◽  
Gizem Çağla Gürpınar
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Aqueous Solutions ◽  
Kinetic Studies ◽  
Second Order ◽  
Order Kinetic ◽  
Adsorption Processes ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Langmuir And Freundlich Models

An activated carbon was prepared from pea shells and used for the removal of methylene blue (MB) from aqueous solutions. The influence of various factors such as adsorbent concentration, initial dye concentration, temperature, contact time, pH, and surfactant was studied. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. The adsorption isotherm was found to follow the Langmuir model. The monolayer sorption capacity of activated carbon prepared from pea shell for MB was found to be 246.91 mg g−1at 25∘C. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes. Kinetic studies showed that the adsorption followed pseudo-second-order kinetic model. Various thermodynamic parameters such as , , and were evaluated. The results in this study indicated that activated carbon prepared from pea shell could be employed as an adsorbent for the removal of MB from aqueous solutions.

scholarly journals Removal of Lead Ions from Waste Water Using Modified Jordanian Zeolite

2020 ◽  
pp. 19-30
Author(s):  
Hutaf M. Baker
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Sodium Dodecyl ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Lead Ions ◽  
Synthetic Wastewater ◽  
Isotherm Models ◽  
Intraparticle Diffusion Model ◽  
Dodecyl Sulfate ◽  
Pseudo Second Order

In this study a Jordanian Zeolite was modified using anionic surfactant which is sodium dodecyl sulfate (sodium dodecyl sulfate). The sorption of Pb(II) from synthetic wastewater by surfactant modified  Zeolite (SMZ) was investigated as a function of temperature. The experimental data was analysed using isotherm models namely Langmuir, Freundlich, Redlich-Peterson and Temkin and kinetic models such as the pseudo- second-order, intraparticle diffusion and the Elovich models in order to understand the mechanism of the interaction between this SMZ and the lead ions. All the isotherm models showed good correlation with the experimental results but Freundlich was the best. The calculated DH was obtained using Langmuir constant (aL), its value of 8.29kJ/mol revealed that the type of sorption is physical oneThe values of RL at all temperatures reflect the favorability of this interaction. The calculated activation energy was 21.126 kJ/mol using the pseudo-second order constant (k2), which indicates that the sorption is physisorption. The intraparticle diffusion model showed multilinearity which means multiple stages there occurred to achieve the removal of lead ions, the first linear curve is due to the boundary layer diffusion and the second linear curve isfor the intraparticle diffusion effect. The adsorption kinetics data fitted also Elovich model.

Synthesis and Characterization of Chitosan templated Mesoporous Silica: Efficient use of Mesoporous Silica in the removal of Cu(II) from Aqueous Solutions

2016 ◽  
Vol 4 (2) ◽  
pp. 105-112
Author(s):  
Lalchhing puii ◽  
◽  
Seung-Mok Lee ◽  
Diwakar Tiwari ◽  
◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Aqueous Solutions ◽  
Background Electrolyte ◽  
Second Order ◽  
Order Kinetic ◽  
Sorption Data ◽  
Column Reactor ◽  
Wide Ph Range ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order

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.

scholarly journals Removal of Chromium(VI) by Chitosan Beads Modified with Sodium Dodecyl Sulfate (SDS)

2020 ◽  
Vol 10 (14) ◽  
pp. 4745
Author(s):  
Xiaoyu Du ◽  
Chihiro Kishima ◽  
Haixin Zhang ◽  
Naoto Miyamoto ◽  
Naoki Kano
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Sodium Dodecyl ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Chitosan Beads ◽  
X Ray ◽  
Chromium Vi ◽  
Dodecyl Sulfate

In this study, chitosan beads modified with sodium dodecyl sulfate (SDS) were successfully synthesized and employed for the removal of chromium(VI) (Cr(VI)). The adsorption performance of the adsorbent (SDS-chitosan beads) was examined by batch experiments. The partition coefficient (PC) as well as the adsorption capacity were evaluated to assess the true performance of the adsorbent in this work. The adsorbent (SDS-chitosan beads) showed a maximum Cr(VI) adsorption capacity of 3.23 mg·g−1 and PC of 9.5 mg·g−1·mM−1 for Cr(VI). The prepared adsorbent was characterized by different techniques such as scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FT-IR). We used inductively coupled plasma mass spectrometry (ICP-MS) for the determination of Cr(VI) in solution. The experimental data could be well-fitted by pseudo-second-order kinetic and Langmuir isotherm models. The thermodynamic studies indicated that the adsorption process was favorable under the higher temperature condition. The SDS-modified chitosan beads synthesized in this work represent a promising adsorbent for removing Cr(VI).

Effect of alcohols on counteriono association in aqueous solutions of sodium dodecyl sulfate

1981 ◽  
Vol 81 (2) ◽  
pp. 536-539 ◽  
Author(s):  
Ajay K. Jain ◽  
R.P.B. Singh
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Aqueous Solutions ◽  
Sodium Dodecyl ◽  
Dodecyl Sulfate
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