Chromium (VI) Adsorption on Activated Lignin

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
Nassima Tazerouti ◽  
Moussa Amrani
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Analytical Data ◽  
Correlation Coefficients ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Chromium Vi ◽  
Pseudo Second Order

Activated lignin, having a surface area of 1023 m2 g-1, has been prepared from lignin sulfate that was treated by 30% H2O2 and carbonized at 300°C in order to test the chromium (VI) adsorption from aqueous solution. The influence of contact time, pH, initial concentration of adsorbent and adsorbate and temperature on the adsorption capacity was investigated. The maximum removal of Cr(VI) was found to be 92.36% at pH=2 and a contact time of 80 min. Optimal concentration of lignin and Cr(VI) was found to be 3.8 gL-1 and 180mg L-1, respectively. The adsorption kinetics was examined with pseudo-first-order and pseudo-second-order equations. The analytical data fit well to the pseudo-second-order equation, and the rate of removal of chromium was found to speed up by increasing the temperature. Activation energy for the adsorption process was found to be 18.19 KJ mol-1. The Langmuir-Freundlich adsorption isotherm models were applied to describe the isotherm and its constants for the adsorption of Cr(VI) on lignin. These constants and correlation coefficients of the isotherm models were calculated and compared with each other. Results indicated that Cr(VI) uptake could be described by the Langmuir adsorption isotherm. The maximum adsorption capacity (qmax) of Cr(VI) on lignin was 75.75 mg g-1 at a temperature of 40°C. The dimensionless equilibrium parameter (RL) signified a favorable adsorption of Cr(VI) on lignin and was found to be between 0.0601 and 0.818 (0L<1). The thermodynamic parameters such as ?G°, ?S°, and ?H° were calculated and it has been found that the reaction was spontaneous and endothermic in nature. This study indicates that lignin has the potential to become an effective and economical adsorbent for the removal of Cr(VI) from waste water.

Chromium (VI) adsorption onto activated sulfate lignin

2009 ◽  
Vol 4 (2) ◽  
Author(s):  
Nassima Tazrouti ◽  
Moussa Amrani
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Analytical Data ◽  
Order Equation ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Adsorption Model ◽  
Chromium Vi ◽  
Pseudo Second Order

Activated lignin having surface area of 1023 m2.g-1 has been prepared from sulfate lignin that was treated by 30 % H2O2 and carbonized at 300 °C in order to test the chromium (VI) adsorption from aqueous solution. The influence of contact time, pH, initial concentration of adsorbent and adsorbate and temperature on the adsorption capacity were investigated. The maximum removal of Cr(VI) was found to be 92,36 % at pH=2 and contact time of 80 min. Optimal concentration of lignin and Cr(VI) were found to be 3.8 g.l-1 and 180 mg.l-1, respectively. The adsorption kinetics was tested pseudo-first-order and pseudo-second-order equation. The analytical data were fitted well in a pseudo-second-order equation and the rate of removal of chromium was found to speed up with increasing temperature. Activation energy for the adsorption process was found to be 18.19 Kj.mol-1. The Langmuir and Freundlich adsorption isotherm models were applied to describe the isotherm and isotherm constants for the adsorption of Cr (VI) on lignin. These constants and correlation coefficients of the isotherm models were calculated and compared. Results indicated that Cr (VI) uptake could be described by the Langmuir adsorption model. The maximum adsorption capacity (qm) of Cr (VI) on lignin was 75.75 mg.g-1 at temperature of 40°C. The dimensionless equilibrium parameter (RL) signified a favorable adsorption of Cr (VI) on lignin and was found between 0.0601 and 0.818 (0&lt;RL&lt;1). The thermodynamic parameters like ΔG°, ΔS° and ΔH° were calculated and it has been found that the reaction was spontaneous and endothermic in nature. This study indicates that lignin has the potential to become an effective and economical adsorbent for removal Cr (VI) from the waste water.

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

2010 ◽  
Vol 5 (1) ◽  
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.

scholarly journals Modified/Unmodified Nanoparticle Adsorbents of Cellulose Origin With High Adsorptive Potential for Removal of Pb(II) From Aqueous Solution

2017 ◽  
Vol 13 (27) ◽  
pp. 425
Author(s):  
Azeh Yakubu ◽  
Gabriel Ademola Olatunji ◽  
Folahan Amoo Adekola
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Process ◽  
Correlation Coefficients ◽  
Solution Temperature ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Kinetics Of Adsorption ◽  
Kinetics Of

This investigation was conducted to evaluate the adsorption capacity of nanoparticles of cellulose origin. Nanoparticles were synthesized by acid hydrolysis of microcrystalline cellulose/cellulose acetate using 64% H3PO4 and characterized using FTIR, XRD, TGA-DTGA, BET and SEM analysis. Adsorption kinetics of Pb (II) ions in aqueous solution was investigated and the effect of initial concentration, pH, time, adsorbent dosage and solution temperature. The results showed that adsorption increased with increasing concentration with removal efficiencies of 60% and 92.99% for Azeh2 and Azeh10 respectively for initial lead concentration of 3 mg/g. The effects of contact time showed that adsorption maximum was attained within 24h of contact time. The maximum adsorption capacity and removal efficiency were achieved at pH6. Small dose of adsorbent had better performance. The kinetics of adsorption was best described by the pseudo-second-Order model while the adsorption mechanism was chemisorption and pore diffusion based on intra-particle diffusion model. The isotherm model was Freundlich. Though, all tested isotherm models relatively showed good correlation coefficients ranging from 0.969-1.000. The adsorption process was exothermic for Azeh-TDI, with a negative value of -12.812 X 103 KJ/mol. This indicates that the adsorption process for Pb by Azeh-TDI was spontaneous. Adsorption by Azeh2 was endothermic in nature.

Biosorption of Cr(VI) from Aqueous Solution by Aspergillus Niger

2011 ◽  
Vol 236-238 ◽  
pp. 155-158
Author(s):  
Li Fang Zhang ◽  
Shu Juan Dai ◽  
Ying Ying Chen
Keyword(s):  
Aqueous Solution ◽  
Aspergillus Niger ◽  
Contact Time ◽  
Correlation Coefficients ◽  
Second Order ◽  
Order Kinetic ◽  
Chromium Vi ◽  
Biosorption Process ◽  
Initial Ph ◽  
Pseudo Second Order

In this study, Biosorption of hexavalent chromium ions from aqueous solution by using biomass ofAspergillus nigerwas investigated. Different parameters such as initial pH, biosorbent amount, contact time and temperature were explored. The biosorption of Cr (VI) ions was highly pH dependent and the optimum pH for biosorption of Cr (VI) ions was found to be 2.0. Biosorption capacity of Cr (VI) ions decreased with increased biosorbent dosage. The biosorption equilibrium was established in about 120min of contact time. Equilibrium uptake of Cr (VI) ions onto biomass increased from 12.57 mg/g at 20°C to 19.48 mg/g at 40 °C for 20mg/L Cr (VI) ions concentration. The biosorption process followed the pseudo-second order kinetic model and the correlation coefficients from the pseudo-second order model were all higher than 0.997 in all studied temperatures. These results suggest that the biomass ofAspergillus nigeris a promising biosorbent for removal of chromium (VI) ions from the wastewater.

scholarly journals Fe3O4@C Matrix with Tailorable Adsorption Capacities for Paracetamol and Acetylsalicylic Acid: Synthesis, Characterization, and Kinetic Modeling

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1727 ◽  
Author(s):  
Elena-Alina Moacă ◽  
Ciprian-Valentin Mihali ◽  
Ioana-Gabriela Macaşoi ◽  
Roxana Racoviceanu (Băbuţă) ◽  
Codruţa Şoica ◽  
...  
Keyword(s):  
Acetylsalicylic Acid ◽  
Magnetic Measurements ◽  
Low Cost ◽  
Correlation Coefficients ◽  
Combustion Method ◽  
Acid Synthesis ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Pseudo Second Order

In this study Fe3O4@C matrix was obtained by combustion method and used hereafter as adsorbent for paracetamol and acetylsalicylic acid removal from aqueous solutions. The Fe3O4@C matrix was characterized by electronic microscopy, X-ray diffraction, thermal analysis, Fourier-transform infrared spectroscopy, and magnetic measurements. Two kinetic models of pseudo first-order and pseudo-second-order for both paracetamol and acetylsalicylic acid were studied. The experimental data were investigated by Langmuir, Freundlich, and Redlich–Peterson adsorption isotherm models. The adsorption followed the Redlich–Peterson and pseudo-second-order models with correlation coefficients R2 = 0.98593 and R2 = 0.99996, respectively, for the adsorption of paracetamol; for the acetylsalicylic acid, the adsorption followed the Freundlich and pseudo-second-order model, with correlation coefficients R2 = 0.99421 and R2 = 0.99977, respectively. The equilibrium was quickly reached after approximately 1h for the paracetamol adsorption and approximately 2h for acetylsalicylic acid adsorption. According to the Langmuir isotherm, the maximum adsorption capacity of the magnetic matrix was 142.01 mg·g−1 for the retention of paracetamol and 234.01 mg·g−1 for the retention of acetylsalicylic acid. The benefits of using the Fe3O4@C matrix are the low cost of synthesis and its easy and fast separation from solution by using an NdBFe magnet.

scholarly journals Cr6+ adsorption by modified vermiculite

2020 ◽  
Author(s):  
Valeria Medoro ◽  
Celia Marcos Pascual ◽  
Giacomo Ferretti ◽  
Giulio Galamini ◽  
Massimo Coltorti
Keyword(s):  
Earth Sciences ◽  
Inductively Coupled Plasma ◽  
Contact Time ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Experimental Conditions ◽  
X Ray ◽  
Pseudo Second Order

&lt;p&gt;&lt;strong&gt;Abstract&lt;/strong&gt;: &lt;strong&gt;Cr&lt;sup&gt;6+&lt;/sup&gt; adsorption by modified vermiculite&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;&amp;#160;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Valeria Medoro- University of Ferrara , Department of Physics and Earth Sciences, Italy&lt;/p&gt;&lt;p&gt;Celia Marcos Pascual-University of Oviedo, Department of Geology, Spain&lt;/p&gt;&lt;p&gt;Giacomo Ferretti- University of Ferrara , Department of Physics and Earth Sciences, Italy&lt;/p&gt;&lt;p&gt;Giulio Galamini- University of Ferrara , Department of Physics and Earth Sciences, Italy&lt;/p&gt;&lt;p&gt;Massimo Coltorti- University of Ferrara , Department of Physics and Earth Sciences, Italy&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;This work aimed at investigating the adsorption of Cr&lt;sup&gt;6+&lt;/sup&gt;&amp;#160;in water by exfoliated vermiculite. The adsorbant tested in this experiment was a vermiculite (from China) which has been subjected to heating at 1000 &amp;#176;C for 1 minute, resulting in an exfoliated vermiculite.&lt;/p&gt;&lt;p&gt;Three effects were studied: 1) contact time; 2) initial concentracion of Cr&lt;sup&gt;6+&lt;/sup&gt;; 3) adsorbent mass. Samples were analysed by X Ray Fluorescence (XRF), X Ray Diffraction (XRD) and the solutions with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to quantify the adsorbed Cr&lt;sup&gt;6+&lt;/sup&gt; by the vermiculite.&lt;/p&gt;&lt;p&gt;Results from XRD diffraction showed a conversion of vermiculite into flogopite&amp;#160; after heating at 1000&amp;#176;C for 1 minute because of: 1) high content of potassium, 2) dehydration and 3) structural re-ordering; after the contact of vermiculite with Cr&lt;sup&gt;6+&lt;/sup&gt;, the mineral structure did not change. The adsorption of Cr&lt;sup&gt;6+&lt;/sup&gt;&amp;#160;was studied by Langmuir, Freundlich and&amp;#160;Dubinin-Kaganer-Radushkevich&amp;#160;(DKR) isotherm models. DKR model, indicative of a cooperative process, described adsorption equilibrium better than the other two models and the maximum adsorption capacity obtained was of 2.81 mol/g. Kinetic was studied using pseudo-first and pseudo-second order kinetic models, with a better description of the process by pseudo-second order model with correlation coefficient almost unitary (R&lt;sup&gt;2&lt;/sup&gt;=0.9984; other kinetic parameters were k&lt;sub&gt;2&lt;/sub&gt;=0.0015 and the absorption initial rate of 0.2x10&lt;sup&gt;-8&lt;/sup&gt; mg g&lt;sup&gt;-1&lt;/sup&gt; h&lt;sup&gt;-1&lt;/sup&gt;).&amp;#160;&lt;/p&gt;&lt;p&gt;The present study demonstrates the effectiveness of modified vermiculite adsorbents for the treatment of hexavalent chromium-contaminated waters and that its adsorption depends on the experimental conditions (such as contact time, initial concentracion of Cr&lt;sup&gt;6+&lt;/sup&gt; and adsorbent mass).&lt;/p&gt;

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

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
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.

Characterization and adsorption performance of chitosan/diatomite membranes for Orange G removal

e-Polymers ◽  
2016 ◽  
Vol 16 (2) ◽  
pp. 99-109 ◽  
Author(s):  
Xiu-Juan Wu ◽  
Ji-De Wang ◽  
Li-Qin Cao
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Ph Value ◽  
Removal Rate ◽  
Composite Membranes ◽  
Second Order ◽  
Inorganic Substances ◽  
Phase Inversion Technique ◽  
Orange G ◽  
Pseudo Second Order

AbstractNovel chitosan/diatomite (CS/DM) membranes were prepared by phase inversion technique to remove anionic azo dyes from wastewater. The fabricated composite membranes exhibited the combined advantages of inorganic substances, diatomites, and polysaccharides. These composite membranes were characterized through Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction analysis. The mechanical properties of the membranes were also evaluated. Adsorption experiments were conducted under varied initial dye concentration, solution pH values, contact time, and adsorbent dosage. The results indicate that pH 3 is the optimal pH value for Orange G adsorption. The CS/DM membranes exhibit the highest adsorption capacity of 588 mg g-1 and removal rate of 94% under an initial dye concentration of 200 mg l-1, contact time of 6 h, and membrane dosage of 8 mg. Langmuir, Freundlich and Redlich-Peterson adsorption models were applied to describe the equilibrium isotherms at different dye concentrations. The equilibrium data was found to be fitted well to the Redlich-Peterson isotherm. Pseudo-first-order and pseudo-second-order kinetics models were used to describe the adsorption of membranes. The adsorption data were well explained by pseudo-second-order models, and also followed by the Elovich model. In addition, these membranes display high adsorption capacity and mechanical performance even after reused for seven times.

Removal of acetaminophen (ACT) from aqueous solution by using nanosilica adsorbent: experimental study, kinetic and isotherm modeling

2020 ◽  
Vol 49 (1) ◽  
pp. 55-62
Author(s):  
Akbar Eslami ◽  
Zahra Goodarzvand Chegini ◽  
Maryam Khashij ◽  
Mohammad Mehralian ◽  
Marjan Hashemi
Keyword(s):  
Removal Rate ◽  
Synthesis Method ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Content Type ◽  
Bet Analysis ◽  
Pseudo Second Order

Purpose A nanosilica adsorbent was prepared and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET. Design/methodology/approach The optimum conditions for the highest adsorption performance were determined by kinetic modeling. The adsorbent was used for the adsorption of acetaminophen (ACT), and the parameters affecting the adsorption were discussed like pH, initial concentration, contact time and adsorbent dosage. The adsorbent have been characterized by SEM, XRD and BET analysis. The kinetic models including pseudo-first-order and pseudo-second-order with Langmuir and Freundlich isotherm models were applied to investigate the kinetic and isotherms parameters. Findings The adsorption of ACT increased to around 95% with the increase of nanosilica concentration to 30 g/L. Moreover, the adsorption process of ACT follows the pseudo-second-order kinetics and the Langmuir isotherm with the maximum adsorption capacity of 609 mg/g. Practical implications This study provided a simple and effective way to prepare of nanoadsorbents. This way was conductive to protect environmental and subsequent application for removal of emerging pollutants from aqueous solutions. Originality/value The novelty of the study is synthesizing the morphological and structural properties of nanosilica-based adsorbent (specific surface area, pore volume and size, shape and capability) and improving its removal rate through optimizing the synthesis method; and studying the capability of synthesis of nanosilica-based adsorbent for removal of ACT as a main emerging pharmaceutical water contaminant.

Adsorption of chromium (VI) from aqueous solutions on activated carbon

1994 ◽  
Vol 30 (9) ◽  
pp. 191-197 ◽  
Author(s):  
R. Leyva Ramos ◽  
A. Juarez Martinez ◽  
R. M. Guerrero Coronado
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Ph Effect ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Experimental Adsorption ◽  
Ph Values ◽  
Chromium Vi ◽  
Adsorption Data

The adsorption isotherm of chromium (VI) on activated carbon was obtained in a batch adsorber. The experimental adsorption data were fitted reasonably well to the Freundlich isotherm. The effect of pH on the adsorption isotherm was investigated at pH values of 4, 6, 7, 8, 10 and 12. It was found that at pH &lt; 6, Cr(VI) was adsorbed and reduced to Cr(III) by the catalytic action of the carbon and that at pH ≥ 12, Cr(VI) was not adsorbed on activated carbon. Maximum adsorption capacity was observed at pH 6 and the adsorption capacity was diminished about 17 times by increasing the pH from 6 to 10. The pH effect was attributed to the different complexes that Cr(VI) can form in aqueous solution. The adsorption isotherm was also affected by the temperature since the adsorption capacity was increased by raising the temperature from 25 to 40°C. It was concluded that Cr(VI) was adsorbed significantly on activated carbon at pH 6 and that the adsorption capacity was greatly dependent upon pH.

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