Equilibrium, kinetic and thermodynamic studies of mercury adsorption on almond shell

The application of almond shell as a low cost natural adsorbent to remove Hg2+ from aqueous solution was investigated. Batch experiments were carried out to evaluate the adsorption capacity of the material. The chemical and physical parameters such as pH, sorbent amount, initial ion concentration, and contact time were optimized for the maximum uptake of mercury onto the solid surface. Adsorption isotherms were expressed by Langmuir and Freundlich adsorption models, and the experimental data were found to fit the Langmuir model rather than the Freundlich. The maximum adsorption capacity obtained from the Langmuir isotherm was 135.13 mg/g. A kinetic study was carried out with pseudo-first-order and pseudo-second-order reaction equations and it was found that the Hg2+ uptake process followed the pseudo-second-order rate expression. The thermodynamic values, ΔG0, ΔH0 and ΔS0, indicated that adsorption was an endothermic and spontaneous process. The potential of this material for mercury elimination was demonstrated by efficient Hg2+ removal from a synthetic effluent.

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Tamanrasset’s Clay Characterization and Use as Low Cost, Ecofriendly and Sustainable Material for Water Treatment: Progress and Challenge in Copper Cu (II)

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.406.457 ◽

2021 ◽

Vol 406 ◽

pp. 457-472

Author(s):

Aicha Kourim ◽

Moulay Abderrahmane Malouki ◽

Aicha Ziouche ◽

Mouna Boulahbal ◽

Madjda Mokhtari

Keyword(s):

Adsorption Capacity ◽

Metal Ion ◽

Low Cost ◽

Ion Concentration ◽

Maximum Adsorption Capacity ◽

X Ray Diffraction ◽

X Ray ◽

Pseudo Second Order ◽

Equilibrium Process

In this study, the adsorption of copper Cu (II) from aqueous solution, on Tamanrasset’s clay which is low cost adsorbent, was studied using batch experiments. The adsorption study includes both equilibrium adsorption isotherms and kinetics. The characterization of the adsorbent necessitated several methods such as X-Ray Diffraction, Scanning Electron Microscopy coupled with Energy Dispersive X-ray, BET for specific surface area determination, Fourier transform infrared spectroscopy and thermogravimetric analysis. Indeed, various parameters were investigated such as contact time, initial metal ion concentration, mass of solid, pH of the solution and temperature. The adsorption process as batch study was investigated under the previews experimental parameters. The results revealed that the adsorption capacity of Cu2+ is maximized at naturel pH of metal 5.5. Removal of copper by the clay of Tamanrasset (kaolinite) achieved equilibrium within 50 minutes; the results obtained were found to be fitted by the pseudo-second order kinetics model. The equilibrium process was well described by the Langmuir model and the maximum adsorption capacity was found to be 26.59 mg/g.

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Kinetic Study of the Bioadsorption of Methylene Blue on the Surface of the Biomass Obtained from the Algae D. antarctica

Journal of Chemistry ◽

10.1155/2018/2124845 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 10

Author(s):

Jhonatan R. Guarín ◽

Juan Carlos Moreno-Pirajan ◽

Liliana Giraldo

Keyword(s):

Methylene Blue ◽

Kinetic Study ◽

Adsorption Capacity ◽

Scientific Community ◽

Second Order ◽

Maximum Adsorption Capacity ◽

Pseudo Second Order ◽

Best Fit ◽

Total Elimination ◽

Purification Of Water

Currently, there is a great pollution of water by the dyes; due to this, several studies have been carried out to remove these compounds. However, the total elimination of these pollutants from the aquatic effluents has represented a great challenge for the scientific community, for which it is necessary to carry out investigations that allow the purification of water. In this work, we studied the bioadsorption of methylene blue on the surface of the biomass obtained from the algae D. antarctica. This material was characterized by SEM and FTIR. To the data obtained in the biosorption experiments, different models of biosorption and kinetics were applied, finding that the best fit to the obtained data is given by applying the pseudo-second-order models and the Toth model, respectively. It was also determined that the maximum adsorption capacity of MB on the surface of the biomass is 702.9 mg/g, which shows that this material has great properties as a bioadsorbent.

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Kinetics of lead ion biosorption from aqueous solution onto lyophilized Aspergillus niveus

Water Practice & Technology ◽

10.2166/wpt.2010.020 ◽

2010 ◽

Vol 5 (1) ◽

Cited By ~ 6

Author(s):

Hülya Karaca ◽

Turgay Tay ◽

Merih Kıvanç

Keyword(s):

Adsorption Capacity ◽

Correlation Coefficients ◽

Freundlich Isotherm ◽

Second Order ◽

Lead Ions ◽

Lead Ion ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Aspergillus Niveus ◽

Pseudo Second Order

The biosorption of lead ions (Pb2+) onto lyophilized fungus Aspergillus niveus was investigated in aqueous solutions in a batch system with respect to pH, contact time and initial concentration of the ions at 30 °C. The maximum adsorption capacity of lyophilized A. niveus was found to be 92.6 mg g−1 at pH 5.1 and the biosorption equilibrium was established about in 30 min. The adsorption capacity obtained is one of the highest value among those reported in the literature. The kinetic data were analyzed using the pseudo-first-order kinetic, pseudo-second-order kinetic, and intraparticle diffusion equations. Kinetic parameters, such as rate constants, equilibrium adsorption capacities, and related correlation coefficients for the kinetic models were calculated and discussed. It was found that the adsorption of lead ions onto lyophilized A. niveus biomass fit the pseudo-second-order kinetic model well. The Langmuir and Freundlich isotherm parameters for the lead ion adsorption were applied and the Langmuir model agreed better with the adsorption of lead ions onto lyophilized A. niveus.

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Adsorption Study of Cu2+ Ions from Aqueous Solutions by Bael Flowers (Aegle marmelos)

Biointerface Research in Applied Chemistry ◽

10.33263/briac114.1189111904 ◽

2020 ◽

Vol 11 (4) ◽

pp. 11891-11904

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Metal Ion ◽

Low Cost ◽

Sem Analysis ◽

Ion Concentration ◽

Maximum Adsorption Capacity ◽

Aegle Marmelos ◽

Batch Mode ◽

Initial Ph

In the present study, batch mode adsorption was carried out to investigate the adsorption capacity of dried bael flowers (Aegle marmelos) for the adsorptive removal of Cu(II) ions from aqueous solutions by varying agitation time, initial metal concentration, the dose of adsorbent, temperature, and initial pH of the Cu(II) ion solution. The percentage removal of 98.7% was observed at 50 ppm initial metal ion concentration, 0.5 g/100.00 cm3 adsorbent dosage, within the contact time of 120 minutes at 30 ºC in the pH range of 4 – 7. The sorption processes of Cu(II) ions was best described by pseudo-second-order kinetics. Langmuir isotherm had a good fit with the experimental data with 0.97 of correlation coefficient (R2), and the maximum adsorption capacity obtained was 23.14 mg g-1 at 30 ºC. The results obtained from sorption thermodynamic studies suggested that the adsorption process is exothermic and spontaneous. SEM analysis showed tubular voids on the adsorbent. FTIR studies indicated the presence of functional groups like hydroxyl, –C-O, –C=O, and amide groups in the adsorbent, which can probably involve in metal ion adsorption. Therefore, dried bael flowers can be considered an effective low-cost adsorbent for treating Cu(II) ions.

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Adsorption of heavy metals from aqueous solutions by Mg–Al–Zn mingled oxides adsorbent

Water Science & Technology ◽

10.2166/wst.2016.329 ◽

2016 ◽

Vol 74 (7) ◽

pp. 1644-1657 ◽

Cited By ~ 8

Author(s):

Mona El-Sayed ◽

Gh. Eshaq ◽

A. E. ElMetwally

Keyword(s):

Heavy Metals ◽

Metal Ion ◽

Second Order ◽

Ion Concentration ◽

Precipitation Method ◽

Isotherm Models ◽

Infrared Spectrometry ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Pseudo Second Order

In our study, Mg–Al–Zn mingled oxides were prepared by the co-precipitation method. The structure, composition, morphology and thermal stability of the synthesized Mg–Al–Zn mingled oxides were analyzed by powder X-ray diffraction, Fourier transform infrared spectrometry, N2 physisorption, scanning electron microscopy, differential scanning calorimetry and thermogravimetry. Batch experiments were performed to study the adsorption behavior of cobalt(II) and nickel(II) as a function of pH, contact time, initial metal ion concentration, and adsorbent dose. The maximum adsorption capacity of Mg–Al–Zn mingled oxides for cobalt and nickel metal ions was 116.7 mg g−1, and 70.4 mg g−1, respectively. The experimental data were analyzed using pseudo-first- and pseudo-second-order kinetic models in linear and nonlinear regression analysis. The kinetic studies showed that the adsorption process could be described by the pseudo-second-order kinetic model. Experimental equilibrium data were well represented by Langmuir and Freundlich isotherm models. Also, the maximum monolayer capacity, qmax, obtained was 113.8 mg g−1, and 79.4 mg g−1 for Co(II), and Ni(II), respectively. Our results showed that Mg–Al–Zn mingled oxides can be used as an efficient adsorbent material for removal of heavy metals from industrial wastewater samples.

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Adsorption of Copper(II) and Mercury(II) Ions onto Chemically-Modified Chitosan Membranes: Equilibrium and Kinetic Properties

Adsorption Science & Technology ◽

10.1260/0263-6174.30.1.1 ◽

2012 ◽

Vol 30 (1) ◽

pp. 1-21 ◽

Cited By ~ 23

Author(s):

R.B. Rabelo ◽

R.S. Vieira ◽

F.M.T. Luna ◽

E. Guibal ◽

M.M. Beppu

Keyword(s):

Adsorption Capacity ◽

Metal Ion ◽

Batch Process ◽

Second Order ◽

Infrared Spectrometry ◽

Maximum Adsorption Capacity ◽

Kinetic Properties ◽

Pseudo Second Order ◽

Ft Ir ◽

Chitosan Membranes

Cross-linked chitosan was synthesized with glutaraldehyde (chitosan–GLA) and epichlorohydrin (chitosan–ECH). The structures of these matrices were characterized by elemental analysis, Fourier-transform infrared spectrometry (FT-IR), the degree of de-acetylation and the surface topography as determined via scanning electron microscopy (SEM). After promoting interaction with the metal ion, the adsorbent was also studied using FT-IR and energy dispersive X-ray spectroscopy (EDXS). Adsorption studies for Cu(II) and Hg(II) ions were carried out in a batch process. The adsorption kinetics were tested using three models, viz. pseudo-first-order, pseudo-second-order and intra-particle diffusion. The experimental kinetic data were best fitted by the pseudo-second-order model for Cu(II) ions (R2 ≥ 0.98) and for Hg(II) ions (R2 = 0.99). Higher rate constants (k2) were obtained for the adsorption of Cu(II) ions onto chitosan–GLA [1.40 g/(mmol h)] and for Hg(II) ions onto raw chitosan [5.65 g/(mmol h)]. The adsorption rate depended on the concentration of Cu(II) and Hg(II) ions on the adsorbent surface and on the quantity of ions adsorbed at equilibrium. At 293 K, the Langmuir–Freundlich model provided a better fit to the adsorption isotherms on both raw and cross-linked chitosan membranes. The maximum adsorption capacity for Cu(II) ions was obtained with the chitosan–GLA matrix (2.7 mmol/g). A maximum adsorption capacity of 3.1 mmol/g was attained for Hg(II) ions onto the chitosan–ECH matrix.

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Treatment of effluent from fertilizer industry by adsorption on willow sawdust-removal of Ni(II) and Cd(II) from the effluent

Ion Exchange Letters ◽

10.35933/iel.2021.13.001 ◽

2021 ◽

pp. 1-12

Author(s):

Raafia Najam ◽

Syed Muzaffar Ali Andrabi

Keyword(s):

Aqueous Solution ◽

Adsorption Process ◽

Low Cost ◽

Second Order ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

The World ◽

Pseudo Second Order ◽

Almost All ◽

Willow Tree

Sawdust of willow has been investigated as an adsorbent for the removal of Ni(II), and Cd(II) ions from aqueous solution. Since willow tree is widely grown in almost all parts of Kashmir, it can be a common most easily available, sustainable, low cost adsorbent for the treatment of wastewaters in this part of the world where growing industrialization is affecting water quality like elsewhere in the world. Therefore, it is worthwhile to investigate the potential of sawdust of willow tree as an adsorbent for the removal of Ni(II) and Cd(II) ions from aqueous solution as a first step. Batch experiments were conducted to study the effect of some parameters such as contact time, initial concentration of metal ions, solution pH and temperature. Langmuir and Freundlich models were employed for the mechanistic analysis of experimental data obtained. Results reveal that in our system adsorption follows the Langmuir isotherm. The maximum adsorption capacity of Ni(II) and Cd(II) were found to be 7.98 and 7.11 mg/g respectively at optimum conditions. The pseudo-ﬁrst-order and pseudo-second-order models were employed for kinetic analysis of adsorption process. The adsorption process follows pseudo-second-order kinetics. The efficacy of the adsorbent in the treatment of effluent from fertilizer factory has been investigated and the results have been found encouraging.

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Highly Effective Covalently Crosslinked Composite Alginate Cryogels for Cationic Dye Removal

Gels ◽

10.3390/gels7040178 ◽

2021 ◽

Vol 7 (4) ◽

pp. 178

Author(s):

Serap Sezen ◽

Vijay Kumar Thakur ◽

Mehmet Murat Ozmen

Keyword(s):

Adsorption Capacity ◽

Dye Removal ◽

Low Cost ◽

Dye Adsorption ◽

Maximum Adsorption Capacity ◽

High Porosity ◽

Order Model ◽

Removal Capacity ◽

Pseudo Second Order ◽

The One

Currently, macroporous hydrogels have been receiving attention in wastewater treatment due to their unique structures. As a natural polymer, alginate is used to remove cationic dyes due to its sustainable features such as abundance, low cost, processability, and being environmentally friendly. Herein, alginate/montmorillonite composite macroporous hydrogels (cryogels) with high porosity, mechanical elasticity, and high adsorption yield for methylene blue (MB) were generated by the one-step cryogelation technique. These cryogels were synthesized by adding montmorillonite into gel precursor, followed by chemical cross-linking employing carbodiimide chemistry in a frozen state. The as-prepared adsorbents were analyzed by FT-IR, SEM, gel fraction, swelling, uniaxial compression, and MB adsorption tests. The results indicated that alginate/montmorillonite cryogels exhibited high gelation yield (up to 80%), colossal water uptake capacity, elasticity, and effective dye adsorption capacity (93.7%). Maximum adsorption capacity against MB was 559.94 mg g−1 by linear regression of Langmuir model onto experimental data. The Pseudo-Second-Order model was fitted better onto kinetic data compared to the Pseudo-First-Order model. Improved porosity and mechanical elasticity yielding enhanced dye removal capacity make them highly potential alternative adsorbents compared to available alginate/montmorillonite materials for MB removal.

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Effectiveness of Alkali-Acid Treatment in Enhancement the Adsorption Capacity for Rice Straw: The Removal of Methylene Blue Dye

ISRN Physical Chemistry ◽

10.1155/2013/208087 ◽

2013 ◽

Vol 2013 ◽

pp. 1-15 ◽

Cited By ~ 19

Author(s):

Nady A. Fathy ◽

Ola I. El-Shafey ◽

Laila B. Khalil

Keyword(s):

Methylene Blue ◽

Adsorption Capacity ◽

Rice Straw ◽

Acid Treatment ◽

Low Cost ◽

Second Order ◽

Isotherm Models ◽

Blue Dye ◽

Acid Modification ◽

Pseudo Second Order

The effectiveness of alkali-acid modification in enhancement the adsorption capacity of rice straw (RS) for removing a basic dye was studied. The obtained adsorbents were characterized by slurry pH, pHPZC, iodine number, methylene blue number, FTIR, and SEM analyses. Adsorption of methylene blue (MB) was described by the Langmuir, Freundlich, Tempkin, and Redlich-Peterson isotherm models. Effects of contact time, initial concentration of MB dye, pH of solution, adsorbent dose, salt concentration of NaCl, and desorbing agents on the removal of MB were reported. Kinetic studies were analyzed using the pseudo-first-order, pseudo-second-order, and the intraparticle diffusion models and were found to follow closely the pseudo-second-order model. Equilibrium data were best represented by the Langmuir and Redlich-Peterson isotherms. The adsorption capacities were varied between 32.6 and 131.5 mg/g for untreated and treated RS samples with NaOH-1M citric acid (ARS-1C), respectively. Adsorption behavior of the ARS-1C sample was experimented in a binary mixture containing methylene blue (basic) and reactive blue 19 (acidic) dyes which showed its ability to remove MB higher than RB19. Overall, the results indicate that the alkali-acid treatment proved to be potential modification for producing effective low-cost adsorbents for the removal of the basic dyes from wastewater.

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Synthesis and characterization of a new magnetic adsorbent for removal of 4-nitrophenol: application of response surface methodology

Water Science & Technology ◽

10.2166/wst.2019.390 ◽

2019 ◽

Vol 80 (8) ◽

pp. 1430-1442

Author(s):

Reza Gholamnia ◽

Mehrnoosh Abtahi ◽

Reza Saeedi ◽

Shokooh Sadat Khaloo

Keyword(s):

Graphene Oxide ◽

Adsorption Capacity ◽

Response Surface ◽

Second Order ◽

Quadratic Model ◽

Maximum Adsorption Capacity ◽

Modified Graphene Oxide ◽

Pseudo Second Order ◽

Modified Graphene ◽

Graphene Oxide Sheets

Abstract Magnetic modified graphene oxide was synthesized as a new modified magnetic nano-composite (MMNC) by a simple sonochemical–hydrothermal method. The sonochemical reaction was employed to exfoliate, functionalize and decorate neomycin on graphene oxide sheets. Nickel ferromagnetic particles were synthesized by hydrothermal co-precipitation method and decorated on neomycin-modified graphene oxide. The morphology and chemical structure of MMNC were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction spectroscopy. The adsorption capability of MMNC for removal of phenolic compounds was assessed through adsorption of 4-nitrophenol (4-NP) from aqueous solution. The three-factor Box–Behnken design coupled with response surface method was applied to evaluate and optimize the important variables which affect the adsorption process. A significant quadratic model (p-value <0.05, R2(adj) = 0.9593) was derived using analysis of variance. The maximum adsorption capacity of 125.4 mg 4-NP/g MMNC at pH 6 was obtained, which was comparable in some cases and higher than most adsorbents reported in the literature. The presence of neomycin on graphene oxide sheets improved the maximum adsorption capacity of the nano-sorbent up to 28% (from 98.7 to 125.4 mg 4-NP/g adsorbent). The adsorption isotherms fitted well with the Langmuir model (Langmuir constant b = 0.064 l/mg, R2 = 0.9989) and the kinetic study showed that the nitrophenol uptake process followed the pseudo-second-order rate expression (R2 ≥ 0.9960, pseudo-second-order constant K2 ≥ 1.7 × 10−3).

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