scholarly journals Glyphosate adsorption by Eucalyptus camaldulensis bark-mediated char and optimization through response surface modeling

2019 ◽  
Vol 9 (7) ◽  
Author(s):  
Kamalesh Sen ◽  
Jayanta Kumar Datta ◽  
Naba Kumar Mondal
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Low Cost ◽  
Eucalyptus Camaldulensis ◽  
Zero Point ◽  
Isotherm Models ◽  
Multilayer Adsorption ◽  
Batch Mode ◽  
Initial Concentration ◽  
Glyphosate Herbicide

Abstract In this study, orthophosphoric acid-modified activated char was prepared from Eucalyptus camaldulensis bark (EBAC), and used for removing traces of [N-(phosphonomethyl)glycine] (glyphosate) herbicide from aqueous solution. The adsorption capacity was characterized by zero-point-charge pH, surface analysis, and Fourier transform infrared spectroscopy. Batch mode experiments were conducted to observe the effects of selected variables, namely dose, contact time, pH, temperature, and initial concentration, on adsorption capacity. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models were generated to describe the mechanisms involved in the multilayer adsorption process. The results show that high temperature enhanced the adsorption capacity of EBAC, with a temperature of 373 K yielding adsorption capacity (qmax) and Freundlich parameter (KF) of 66.76 mg g−1 and 9.64 (mg g−1) (L mg−1)−n, respectively. The thermodynamics study revealed entropy and enthalpy of −5281.3 J mol−1 and −20.416 J mol−1, respectively. Finally, glyphosate adsorption was optimized by the Box–Behnken model, and optimal conditions were recorded as initial concentration of 20.28 mg L−1, pH 10.18, adsorbent dose of 199.92 mg/50 mL, temperature of 303.23 K, and contact time of 78.42 min, with removal efficiency of 98%. Therefore, it can be suggested that EBAC could be used as an efficient, low-cost adsorbent for removal of glyphosate from aqueous solutions.

scholarly journals ADSORPTION OF FLUORIDE USING SIO2 NANOPARTICLES AS ADSORBENT

2020 ◽  
Vol 2 (2) ◽  
pp. 1-9
Author(s):  
Davoud Balarak ◽  
Yousef Mahdavi ◽  
Ali Joghatayi
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Sio2 Nanoparticles ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Initial Concentration ◽  
High Doses

Presence of Fluoride in water is safe and effective when used as directed, but it can be harmful at high doses. In the present paper SiO2 nanoparticles as a adsorbent is used for removal of fluoride from aqueous solution. The effect of various operating parameters such as initial concentration of F-, Contact time, adsorbent dosage and pH were investigated. Equilibrium isotherms were used to identify the possible mechanism of the adsorption process. Maximum adsorption capacity of the SiO2 nanoparticles was 49.95 mg/g at PH=6, contact time 20 min, initial concentration of 25 mg/L, and 25±2 ◦C temperatures, when 99.4% of Fwere removed. The adsorption equilibriums were analyzed by Langmuir and Freundlich isotherm models. It was found that the data fitted to Langmuir (R2=0.992) better than Freundlich (R2=0.943) model. Kinetic analyses were conducted using pseudo first-and second-order models. The regression results showed that the adsorption kinetics was more accurately represented by a pseudo second-order model. These results indicate that SiO2 nanoparticles can be used as an effective, low-cost adsorbent to remove fluoride from aqueous solution.

Determination of Adsorption Capacity of Agricultural-Based Carbon for Ni (II) Adsorption from Aqueous Solution

2014 ◽  
Vol 567 ◽  
pp. 20-25 ◽  
Author(s):  
Taimur Khan ◽  
Mohamed Hasnain Isa ◽  
Malay Chaudhuri ◽  
Raza Ul Mustafa Muhammad ◽  
Mohamed Osman Saeed
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Rice Husk ◽  
Contact Time ◽  
Low Cost ◽  
Equilibrium Adsorption ◽  
Batch Adsorption ◽  
Average Pore ◽  
Initial Concentration ◽  
Rice Husk Carbon

The aim of the study was to prepare potentially cheaper carbon for the adsorptive removal of Nickle [Ni (II)] from aqueous solution. The adsorption capacity of the prepared carbon to remove Ni (II) from aqueous solution was determined and adsorption mechanism was investigated. Rice husk carbon was prepared by incineration in a muffle furnace. The incinerated rice husk carbon (IRHC) was characterised in terms of surface area, micropore area, micropore volume, average pore diameter and surface morphology. Adsorption of Ni (II) by IRHC was examined. The influence of operating parameters, namely, pH, initial concentration and contact time on adsorption of Ni (II) by IRHC was evaluated. Batch adsorption tests showed that extent of Ni (II) adsorption depended on initial concentration, contact time and pH. Equilibrium adsorption was achieved in 120 min, while maximum Ni (II) adsorption occurred at pH 4. Langmuir and Freundlich isotherms were studied and the equilibrium adsorption data was found to fit well with the Langmuir isotherm model. Langmuir constants Q° and b were 14.45 and 0.10, and Freundlich constants Kf and 1/n were 4.0 and 0.26, respectively. Adsorption of Ni (II) by IRHC followed pseudo-second-order kinetics. Being a low-cost carbon, IRHC has potential to be used for the adsorption of Ni (II) from aqueous solution and wastewater in developing countries.

scholarly journals Adsorption of Fluoride Ion onto Zirconyl-Impregnated Activated Carbon Prepared from Lapsi Seed Stone

2013 ◽  
Vol 30 ◽  
pp. 13-23 ◽  
Author(s):  
Sahira Joshi ◽  
Mandira Adhikari ◽  
Raja Ram Pradhananga
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Zinc Chloride ◽  
Contact Time ◽  
Activated Carbons ◽  
Low Cost ◽  
Chemical Society ◽  
Nitrogen Atmosphere ◽  
Batch Mode ◽  
Fluoride Adsorption

The potentials of activated carbon derived from Lapsi (Choerospondias axillaries) seed stone after impregnation with zirconium for adsorptive removal of fluoride is presented. Activated carbons from Lapsi seed stone were prepared by three different techniques. Firstly by directly burning in limited supply of air, secondly by treating with a mixture of conc. H2SO4 and HNO3 (in the ratio of 1:1 by weight) and thirdly by activation with zinc chloride (in the ratio of 1:1 by weight) followed by carbonization at 400°C and 500°C under nitrogen atmosphere. Thus prepared carbons were impregnated with zirconyl oxychloride and effects of pH, adsorbent dose, and contact time and adsorbate concentration for the removal of fluoride were evaluated by batch mode. The optimum pH for adsorption of fluoride was observed at pH 3-4, and a minimum contact time for the maximum defluoridation was found to be 180 min. The Langmuir and Freundlich isotherms were used to describe adsorption equilibrium. Zirconium impregnation increased the fluoride adsorption capacity of carbon to considerable extent. Among carbon prepared by three different techniques, the carbon prepared from zinc chloride activation followed by carbonization showed relatively higher fluoride adsorption capacity. From the experiment it is concluded that activated carbon prepared from Lapsi seed is an efficient, low-cost alternative to commercial activated carbon for defluoridation of water.DOI: http://dx.doi.org/10.3126/jncs.v30i0.9330Journal of Nepal Chemical Society Vol. 30, 2012 Page:  13-23 Uploaded date: 12/16/2013    

scholarly journals KINETIC, ISOTHERM AND EQUILIBRIUM STUDY OF ADSORPTION CAPACITY OF HYDROGEN SULFIDE-WASTEWATER SYSTEM USING MODIFIED EGGSHELLS

2017 ◽  
Vol 18 (1) ◽  
pp. 13-25 ◽  
Author(s):  
O A Habeeb ◽  
K Ramesh ◽  
Gomaa A. M. Ali ◽  
R M Yunus ◽  
O A Olalere
Keyword(s):  
Hydrogen Sulfide ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Batch Mode ◽  
Initial Concentration ◽  
Equilibrium Study ◽  
Operating Variables ◽  
H2s Adsorption ◽  
Analytical Approaches ◽  
Kinetics Of

The studies of adsorption equilibrium isotherm and kinetics of hydrogen sulfide-water systems on calcite-based adsorbents prepared from eggshell are undertaken. The effects of operating variables such as contact time and initial concentration on the adsorption capacity of hydrogen sulfide are investigated. The modified eggshells are characterized by using different analytical approaches such as Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR). The batch mode adsorption process is performed at optimum removal conditions: dosage of 1 g/L, pH level of pH 6, agitation speed of 150 rpm and contact time of 14h for adsorbing hydrogen sulfide with an initial concentration of 100-500 mg/L. In the current study, the Langmuir, Freundlich, Temkin, and Dubinin models are used to predict the adsorption isotherms. Our equilibrium data for hydrogen sulfide adsorption agrees well with those of the Langmuir equation. The maximum monolayer adsorption capacity is 150.07 mg/g. Moreover, the kinetics of H2S adsorption by using the modified calcite of eggshell follows a pseudo-second-order model. From the current work, we have found that the calcite eggshell is a suitable adsorbent for H2S embeded inside the waste water. Most importantly, chicken eggshell is a waste and vastly available; hence, it could serve as a practical mean for H2S adsorption.

Adsorption of Hexavalent Chromium by Eucalyptus camaldulensis bark/maghemite Nano Composite

2018 ◽  
Vol 16 (12) ◽  
Author(s):  
Fatma Elcin Erkurt ◽  
Behzat Balci ◽  
Emine Su Turan
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Low Cost ◽  
Eucalyptus Camaldulensis ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
X Ray Diffraction ◽  
Nano Composite ◽  
X Ray ◽  
Independent Parameters

Abstract In the present study, Eucalyptus camaldulensis bark/maghemite composite (ECMC) was used for potential application as a low-cost adsorbent for the removal of Cr(VI) from aqueous solution. The structural characterization, morphology and elemental analysis of ECMC were performed by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray (EDX) and X-ray Diffraction (XRD). The effects of various independent parameters, contact time, initial Cr(VI) concentration, temperature, pH, and adsorption were investigated. It was found that the adsorption capacity of ECMC increases with increasing Cr(VI) concentration and temperature. The optimum pH was found to be 2 for the removal of Cr(VI) by ECMC. The adsorption capacity was found to be 70.1 mg/g with 0.1 g ECMC at pH 2 and 30 °C. Additionally, 10 and 50 mg/L Cr(VI) were removed from 100 mL aqueous solution by 0.1 g ECMC with 99 % and 93.46 % removal efficiencies, respectively. Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Jovanovic, Smith, Koble Korringen, Vieth-Sladek and Sips Isotherm Models were applied to the experimental data to understand the adsorption mechanism better. The Freundlich Isotherm Model described the adsorption process better (R2 = 0.991) among the other isotherms studied.

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

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.

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.

Nanoparticle Fe3O4 magnetized activated carbon from Armeniaca sibirica shell for the adsorption of Hg(II) ions

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Initial Concentration

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0，enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.

ADSORPTION OF ACID ORANGE 7 BY CETYLPYRIDINIUM BROMIDE MODIFIED SUGARCANE BAGASSE

2016 ◽  
Vol 78 (1-2) ◽  
Author(s):  
Nik Ahmad Nizam Nik Malek ◽  
Nurain Mat Sihat ◽  
Mahmud A. S. Khalifa ◽  
Auni Afiqah Kamaru ◽  
Nor Suriani Sani
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Sugarcane Bagasse ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Acid Orange 7 ◽  
Cetylpyridinium Bromide ◽  
Batch Mode ◽  
Acid Orange ◽  
Adsorption Data

In the present study, the adsorption of acid orange 7 (AO7) dye from aqueous solution by sugarcane bagasse (SB) and cetylpyridinium bromide (CPBr) modified sugarcane bagasse (SBC) was examined. SBC was prepared by reacting SB with different concentrations (0.1, 1.0 and 4.0 mM) of cationic surfactant, CPBr. The SB and SBC were characterized using Fourier transform infrared (FTIR) spectroscopy. The adsorption experiments were carried out in a batch mode. The effect of initial AO7 concentrations (5-1000 mg/L), initial CPBr concentrations and pH of AO7 solution (2-9) on the adsorption capacity of SB and SBC were investigated. The experimental adsorption data were analyzed using Langmuir and Freundlich isotherm models. The adsorption of AO7 onto SB and SBC followed Freundlich and Langmuir isotherm models, respectively. The maximum uptake of AO7 was obtained by SBC4.0 (SB treated with 4.0 mMCPBr) with the adsorption capacity of 144.928 mg/g. The highest AO7 removal was found to be at pH 2 and 7 for SB and SBC, respectively. As a conclusion, sugarcane bagasse modified with CPBr can become an alternative adsorbent for the removal of anionic compounds in aqueous solution.

scholarly journals Equilibrium, Kinetics, and Thermodynamics of the Removal of Nickel(II) from Aqueous Solution Using Cow Hooves

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
I. Osasona ◽  
O. O. Ajayi ◽  
A. O. Adebayo
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Room Temperature ◽  
Physical Adsorption ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Equilibrium Studies ◽  
Equilibrium Data

The feasibility of using powdered cow hooves (CH) for removing Ni2+ from aqueous solution was investigated through batch studies. The study was conducted to determine the effect of pH, adsorbent dosage, contact time, adsorbent particle size, and temperature on the adsorption capacity of CH. Equilibrium studies were conducted using initial concentration of Ni2+ ranging from 15 to 100 mgL−1 at 208, 308, and 318 K, respectively. The results of our investigation at room temperature indicated that maximum adsorption of Ni2+ occurred at pH 7 and contact time of 20 minutes. The thermodynamics of the adsorption of Ni2+ onto CH showed that the process was spontaneous and endothermic. Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were used to quantitatively analysed the equilibrium data. The equilibrium data were best fitted by Freundlich isotherm model, while the adsorption kinetics was well described by pseudo-second-order kinetic equation. The mean adsorption energy obtained from the D-R isotherm revealed that the adsorption process was dominated by physical adsorption. Powdered cow hooves could be utilized as a low-cost adsorbent at room temperature under the conditions of pH 7 and a contact time of 20 minutes for the removal of Ni(II) from aqueous solution.

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