scholarly journals Adsorption of brilliant green dye on Nephelium mutabile (Pulasan) leaves

2018 ◽  
Vol 17 (1) ◽  
Author(s):  
Nur Afiqah Hazirah Mohamad Zaidi ◽  
Liew Wei Jing ◽  
Linda B. L. Lim
Keyword(s):  
Experimental Data ◽  
Contact Time ◽  
Brilliant Green ◽  
Cost Effective ◽  
Point Of Zero Charge ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Batch Experiments ◽  
Adsorption Method ◽  
Experimental Conditions

The main objective of this study is to investigate the ability of Nephelium mutabile (Pulasan) leaves (PL) in removing toxic brilliant green (BG) dye using the adsorption method. Batch experiments were conducted on the adsorption of BG dye using PL with a contact time of 3.5 h. Adsorption isotherm studies were analysed using six isotherm models, namely Langmuir, Freundlich, Temkin, Dubinin-Radushkevich (D-R), Redlich-Peterson (R-P) and Sips, and the results showed that Sips is the model that best fits the experimental data, with a maximum adsorption capacity (amax) of 130.3 mg g-1. The point of zero charge (pHPZC) of PL was found to be at pH 5.29. Regeneration studies showed that PL can be recovered and reused, especially after treatment with NaOH. This study demonstrates that PL can be considered as a reasonably good and cost-effective biosorbent for BG under our experimental conditions.

scholarly journals Removal of Methyl Violet 2B from Aqueous Solution Using Casuarina equisetifolia Needle

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Muhammad Khairud Dahri ◽  
Muhammad Raziq Rahimi Kooh ◽  
Linda B. L. Lim
Keyword(s):  
Experimental Data ◽  
Contact Time ◽  
Methyl Violet ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Casuarina Equisetifolia ◽  
Dye Pollutants ◽  
Methyl Violet 2B ◽  
Before And After

One of the major contaminants of water bodies is dye pollutants that come from textile, paper, and leather industries. In this study, Casuarina equisetifolia needle (CEN) is used to remove methyl violet 2B (MV) from aqueous solutions. Batch experiments were done to investigate the contact time, effect of pH, initial dye concentrations, and temperature. Langmuir and Freundlich isotherm models were used to describe the interaction between the adsorbate and adsorbent. The sorption mechanism was described using Lagergren 1st order, pseudo 2nd order, and Weber-Morris intraparticle diffusion models. FTIR spectroscopy was used to analyze the functional groups of CEN before and after sorption with MV. Optimal conditions were found to be at room temperature with 2 h contact time and no pH adjustment was needed. Experimental data was best fitted onto Langmuir model with maximum adsorption capacity of 164.99 mg/g, while pseudo 2nd order best described the experimental data for the kinetics study. Thermodynamic parameters such as change in Gibbs free energy (), enthalpy (), and entropy () were also investigated.

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

<p><strong>Abstract</strong>: <strong>Cr<sup>6+</sup> adsorption by modified vermiculite</strong></p><p><strong> </strong></p><p>Valeria Medoro- University of Ferrara , Department of Physics and Earth Sciences, Italy</p><p>Celia Marcos Pascual-University of Oviedo, Department of Geology, Spain</p><p>Giacomo Ferretti- University of Ferrara , Department of Physics and Earth Sciences, Italy</p><p>Giulio Galamini- University of Ferrara , Department of Physics and Earth Sciences, Italy</p><p>Massimo Coltorti- University of Ferrara , Department of Physics and Earth Sciences, Italy</p><p> </p><p>This work aimed at investigating the adsorption of Cr<sup>6+</sup> in water by exfoliated vermiculite. The adsorbant tested in this experiment was a vermiculite (from China) which has been subjected to heating at 1000 °C for 1 minute, resulting in an exfoliated vermiculite.</p><p>Three effects were studied: 1) contact time; 2) initial concentracion of Cr<sup>6+</sup>; 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<sup>6+</sup> by the vermiculite.</p><p>Results from XRD diffraction showed a conversion of vermiculite into flogopite  after heating at 1000°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<sup>6+</sup>, the mineral structure did not change. The adsorption of Cr<sup>6+</sup> was studied by Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich (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<sup>2</sup>=0.9984; other kinetic parameters were k<sub>2</sub>=0.0015 and the absorption initial rate of 0.2x10<sup>-8</sup> mg g<sup>-1</sup> h<sup>-1</sup>). </p><p>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<sup>6+</sup> and adsorbent mass).</p>

scholarly journals Adsorption of Chromium(VI) onto Freshwater Snail Shell-Derived Biosorbent from Aqueous Solutions: Equilibrium, Kinetics, and Thermodynamics

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Xuan Hoa Vu ◽  
Lan Huong Nguyen ◽  
Huu Tap Van ◽  
Dinh Vinh Nguyen ◽  
Thu Huong Nguyen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Low Cost ◽  
Freshwater Snail ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Adsorption Mechanisms

In this study, freshwater snail shells (FSSs) containing CaCO3 were used as a low-cost biosorbent for removing Cr(VI) from aqueous solutions. The characteristics of FSS and mechanism of Cr(VI) adsorption onto FSS were investigated. The FSS biosorbent was characterized using nitrogen adsorption/desorption isotherm, X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. The adsorption mechanism was determined by conducting various batch adsorption experiments along with fitting experimental data with various adsorption models. Batch adsorption experiments were conducted as a function of solution pH, contact time, biosorbent dose, and initial Cr(VI) concentration. Results indicated that pH = 2, a contact time of 120 min, and an initial Cr(VI) concentration of 30 mg/L at 20°C were the best conditions for adsorption of Cr(VI) onto FSS. The Cr(VI) adsorption onto FSS decreased with an increase in temperature from 20 to 40°C. The obtained maximum adsorption capacity was 8.85 mg/g for 2 g/L of FSS dose with 30 mg/L of initial Cr(VI) at 20°C. The adsorption equilibrium data fit well with the Sips and Langmuir isotherm models at 20°C with a high R2 of 0.981 and 0.975, respectively. Also, a good correlation between the experimental data and the pseudo-second-order model was achieved, with the highest R2 of 0.995 at 20°C. The adsorption mechanisms were electrostatic interaction and ion exchange. Simultaneously, this mechanism was also controlled by film diffusion. The Cr(VI) adsorption process was irreversible, spontaneous (−∆G°), exothermic (∆H° is negative), and less random (∆S° is negative). In conclusion, freshwater snail shells have the potential as a renewable adsorbent to remove toxic metals from wastewater.

scholarly journals DEVELOPMENT AND VALIDATION OF A SPECTROPHOTOMETRIC METHOD TO EVALUATE BIOSAFETY CAPACITY OF BARU (Dipteryx alata) PEELS

2018 ◽  
Vol 15 (30) ◽  
pp. 221-240
Author(s):  
E. C. CESARINO ◽  
D. S. MULHOLLAND ◽  
W. FRANCISCO
Keyword(s):  
Contact Time ◽  
Limit Of Detection ◽  
Copper Ions ◽  
Maximum Adsorption Capacity ◽  
Limit Of Quantification ◽  
Experimental Conditions ◽  
Inorganic Matter ◽  
Pseudo Second Order ◽  
Development And Validation ◽  
Dipteryx Alata

This study developed a new analytical method using Molecular Absorption Spectroscopy (MAS) to track the ion cover in adsorption solution per peel (mesocarp) of Baru (Dipteryx alata). The adsorption study was conducted at different pH and contact time (kinetic), encountering 4.0 as the best pH for adsorption experimental conditions. The variation of contact time showed a pseudo-second-order adsorption kinetic behavior. The interpretation of the isotherms allowed to approach the Langmuir model with R² of 0.918 and to determine the maximum adsorption capacity (qmáx) as 11.481 mg.g⁻¹. The characterization of biomass by MAS in the Infrared (FT-IR) identified the possible functional groups belonging to protein, fatty acids and lipids, while thermal analysis (TG-DSC) showed a greater removal of inorganic matter by the biomass washed with water. The method underwent analytical validation, being classified as specific, sensitive, linear, robust, precise and accurate, with LD (limit of detection) and LQ (limit of quantification) equal to 3.873 and 12.912 mg.L⁻¹, respectively. The results obtained demonstrated the potential use of mesocarp Baru as a natural adsorbent for copper ions in solution, opening power for future expansion and improvement of the method.

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.

scholarly journals Utilization to Remove Pb (II) Ions from Aqueous Environments Using Waste Fish Bones by Ion Exchange

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Bayram Kizilkaya ◽  
A. Adem Tekınay
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Mechanism ◽  
Cost Effective ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Fish Bones ◽  
Adsorption Capacities ◽  
Aqueous Environments ◽  
Equilibrium Data ◽  
Pseudo Second Order

Removal of lead (II) from aqueous solutions was studied by using pretreated fish bones as natural, cost-effective, waste sorbents. The effect of pH, contact time, temperature, and metal concentration on the adsorption capacities of the adsorbent was investigated. The maximum adsorption capacity for Pb (II) was found to be 323 mg/g at optimum conditions. The experiments showed that when pH increased, an increase in the adsorbed amount of metal of the fish bones was observed. The kinetic results of adsorption obeyed a pseudo second-order model. Freundlich and Langmuir isotherm models were applied to experimental equilibrium data of Pb (II) adsorption and the value ofRLfor Pb (II) was found to be 0.906. The thermodynamic parameters related to the adsorption process such asEa,ΔG°,ΔH°, andΔS° were calculated andEa,ΔH°, andΔS° were found to be 7.06, 46.01 kJ mol−1, and 0.141 kJ mol−1K−1for Pb (III), respectively.ΔH° values (46.01 kJmol−1) showed that the adsorption mechanism was endothermic. Weber-Morris and Urano-Tachikawa diffusion models were also applied to the experimental equilibrium data. The fish bones were effectively used as sorbent for the removal of Pb (II) ions from aqueous solutions.

Copper Biosorption and Bioprecipitation by Eichhornia spp. and Sulphate Reducing Bacteria

2009 ◽  
Vol 71-73 ◽  
pp. 561-564
Author(s):  
Shailesh R. Dave ◽  
M.S. Damani ◽  
D.R. Tipre
Keyword(s):  
Contact Time ◽  
Copper Removal ◽  
Point Of Zero Charge ◽  
Experimental Conditions ◽  
Element Analysis ◽  
Freundlich Isotherms ◽  
Biomass Influence ◽  
Reducing Bacteria ◽  
Influence Of Ph ◽  
Copper Sorption

Eichhornia spp. biomass collected from Chandola lake, Ahmedabad, Gujarat, India. Point of zero charge of the biomass was pH 7.3. Flask study showed pH 5 and 2 to 3 h contact time as optimum conditions for copper sorption. In 24 h of contact time, as high as 85% of copper was removed from 100 ppm copper containing solution. In first 2 h of the contact time the removal reached to 67.25%. Copper loading capacity of the biomass ranged between 2.85 to 1.0 g per 100 g of biomass. Influence of pH, temperature, nickel and zinc was studied by 24 factorial experiments. Under the experimental conditions pH and interactions between pH-nickel, temperature-pH and temperature-pH-nickel-zinc were found to be significant with 60 to 74.7% copper removal. As high as 95% of sorbed copper was desorbed with 0.1 N HNO3. Langmuir and Freundlich isotherms were also studied. Reactor study showed 90% overall copper removal from 25 L of copper containing waste and sulfatereducing bacteria played a significant role. Treatment of actual waste also showed 61% of copper removal. SEMquant element analysis showed presence of 12.39% w/w of copper in the biomass exposed to the waste, where as only 0.0018% of copper was detected in unexposed biomas

scholarly journals Optimization, equilibrium and kinetic studies of Zn2+ and Ni2+ adsorption from aqueous solutions using composite adsorbent

2018 ◽  
Vol 67 (3) ◽  
pp. 279-290 ◽  
Author(s):  
Haider M. Zwain ◽  
Mohammadtaghi Vakili ◽  
Irvan Dahlan
Keyword(s):  
Contact Time ◽  
Coal Fly Ash ◽  
Sol Gel ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Isotherm Models ◽  
Experimental Conditions ◽  
Palm Oil Fuel Ash ◽  
Composite Adsorbent ◽  
Oil Fuel

Abstract A novel RHA/PFA/CFA composite adsorbent was synthesized from rice husk ash (RHA), palm oil fuel ash (PFA), and coal fly ash (CFA) by modified sol-gel method. Effect of different parameters such as adsorbent dosage, contact time, and pH were studied using batch experiment to optimize the maximum zinc (Zn2+) and nickel (Ni2) adsorption conditions. Results showed that the maximum adsorption condition occurred at adsorbent amount of 10 g/L, contact time of 60 min, and pH 7. At this condition, the removal efficiencies were 81% and 61% for Zn2+ and Ni2+, in which the adsorption capacities (qmax) were 21.74 mg/g and 17.85 mg/g, respectively. Adsorption behavior of RHA/PFA/CFA composite adsorbent was studied through the various isotherm models at different adsorbent amounts. The results indicated that the Freundlich isotherm model gave an excellent agreement with the experimental conditions. Based on the results obtained from the kinetic studies, pseudo-second-order was suitable for the adsorption of Ni2+ and Zn2+, compared to the pseudo-first-order model. The results presented in this study showed that RHA/PFA/CFA composite adsorbent successfully adsorbed Zn2+ and Ni2.

scholarly journals Recovery and Then Individual Separation of Platinum, Palladium, and Rhodium from Spent Car Catalytic Converters Using Hydrometallurgical Technique followed by Successive Precipitation Methods

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Ahmed M. Yousif
Keyword(s):  
Contact Time ◽  
Catalytic Converter ◽  
Economic Value ◽  
Hydrogen Atmosphere ◽  
Catalytic Converters ◽  
Batch Experiments ◽  
Experimental Conditions ◽  
Leaching Process ◽  
Manufactured Products ◽  
Leaching Solution

Recovery of PGMs (especially rhodium, platinum, and palladium) from different spent manufactured products (like catalytic converters) is considered as an important task as they are rarely found in nature, and they possess high economic value. In this work, the honeycomb of a car catalytic converter was primarily processed by crushing, grinding, and then treating in a hydrogen atmosphere. In order to establish an economic and ecofriendly method for the recovery of studied PGMs, different experimental conditions of changing HCl/H2O2 (as a leaching solution) ratio, temperature, and contact time were studied through batch experiments to obtain the optimum leaching conditions. The use of 0.8 vol% H2O2 and 9.0 M HCl mixture at 60°C for a contact time of 2.5 hours during the leaching process may be considered as the best conditions to be followed to save chemicals, energy, and time (about 86%, 96%, and 98% of Rh, Pt, and Pd were recovered, respectively). Individual separation of PGM ions from each other using precipitation technique from their leaching liquor was performed where % purity values of 99.5, 99.3, and 95.5 were obtained for Pt, Pd, and Rh, respectively.

Ammonium Removal from Aqueous Solutions Using an Ammonium Ion-Exchange Material, the Equilibrium Study

2011 ◽  
Vol 322 ◽  
pp. 102-107
Author(s):  
Lu Hua You ◽  
Xin Tan ◽  
Qiong Qiong Liu ◽  
Lin Zhao
Keyword(s):  
Ion Exchange ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Solution Concentration ◽  
Initial Solution ◽  
Ammonium Ion ◽  
Isotherm Models ◽  
Experimental Conditions ◽  
Initial Solution Concentration ◽  
Exchange Material

This article investigates the removal of ammonium from aqueous solutions using the ammonium ion-exchange material prepared by the modified kaolin. Batch tests were performed under a range of conditions to assess the effect of initial solution concentration, contact time and solution PH on the performance and capacity of the media for this application. The findings show that increasing initial solution concentration and contact time provide the best performance at an optimum PH of between 6 and 7 and the maximum ammonium adsorption capacity reaches at 79mgNH4+g-1 under the experimental conditions studied. Five isotherm models were used to describe the isotherm data. Three-parameter isotherm models (Redlich–Peterson and Langmuir–Freundlich) prove a better fit than two-parameter isotherm models (Langmuir, Freundlich and Temkin). These results indicate that the ammonium ion-exchange material is a promising material for cost-effective removal of ammonium from wastewater.

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