freundlich adsorption isotherm
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2021 ◽  
Vol 1 ◽  
pp. 80-87
Author(s):  
Neni Damajanti ◽  
Anwar Ma’ruf ◽  
Hanafi Khafid Nugraha

Zeolite as an adsorbent has been widely used. Zeolite activation was carried out to increase the absorption. This study aimed to determine the characteristics of the active zeolite and apply it as an adsorbent. The activation process was carried out by adding acid and calcining at 4500C for 6 hours. Remazol Yellow FG is a dye that is widely used in the textile industry. In this study, the adsorption process was carried out on the Remazol Yellow FG solution, then analyzed the effect of changes in pH (5, 6, 7, 8, 9), contact time (30, 60, 90, 120, 150 minutes) and the concentration of Remazol Yellow FG solution ( 50, 100, 150, 200, 250 ppm) on the adsorption of Remazol Yellow FG dye. From the analysis of the sample solution of Remazol Yellow, the values of Ce and qe can be calculated. These values were then used to calculate KL and KF in the Langmuir adsorption isotherm and Freundlich adsorption isotherm models. From the experimental results, it could be seen that as the contact time increased, the adsorption capacity would be greater. However, when the zeolite was already in the saturated phase, the adsorption capacity would tend to decrease. In the Langmuir adsorption isotherm, the KL value was 0.0274 L/mg and in the Freundlich adsorption isotherm model, the KF value was 29.25 L/mg. Remazol Yellow FG adsorption tended to follow the Langmuir adsorption isotherm model with an R2 value of 0.998.


2021 ◽  
Vol 37 (5) ◽  
pp. 1096-1101
Author(s):  
Priyanka Rathore ◽  
Rashmi Verma

The present study removal of toxic heavy metal Cr (VI) ion on bentonite clay from aqueous solution under different experimental conditions and also study sorption capacity are effect different pH, concentration, temperature and contact time of shaking.My study focused on use of bentonite clay as a best adsorbent for the removal of toxic heavy metal Cr (VI) ions from aqueous solution. Initial metal ions concentration increases 50 to 250mgL-1 the % removal Cr (VI) ion decreases from 66.64 % to 53.94 % but amount of sorption increases from 0.833 to 3.371mgg-1, The particle size of bentonite clay increase from 45 to 150μ by amount of adsorption of Cr (VI) decreasing from1.589 mgg-1 to 1.153mgg-1 , pH increasing from 2.0 to 10.0 the amount of sorption decrease from 2.018 to 1.161 mgg-1, temperature increasing from 303K to 313K adsorption is also increases from 1.589 to 1.822mgg-1. Kinetic study for value of rate constant k1 and k2 is favour concentration increases the amounts of the metals sorbent qcal also increases. Q and kf sorption capacity related to Langmuir and Freundlich adsorption isotherm constant. Value of both is favour sorption is temperature dependent. Thermodynamic study the value of ΔG0 increase -1.402 to -2.655it is best evidence temperature increases from 303K to 323K the adsorption of Cr (VI) ion increases because value of ΔG0 is negative favour the adsorption. My investigation best evidence the value of kinetic, equilibrium and thermodynamic parameter also favours the Sorption of Cr (VI) ion on bentonite clay from aqueous solution.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Buhani ◽  
Suharso ◽  
Nurul Miftahza ◽  
Desy Permatasari ◽  
Sumadi

In this research, biomass modification of Nannochloropsis sp. with surfactant cetyltrimethylammonium bromide (CTAB) through a cation exchange reaction to produce adsorbent Nannochloropsis sp.-cetyltrimethylammonium bromide (AlgN-CTAB) has been carried out. Biomass modification of Nannochloropsis sp. by CTAB has been successfully carried out through confirmation from the analysis data produced by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDX). AlgN-CTAB adsorbent has been tested for its adsorption ability against anionic dye of methyl orange (MO) in solution by way of a sequence of experiments by the batch method. The optimum conditions for MO removal from the solution occurred at an adsorbent quantity of 0.1 g, pH of 5, and an interaction time of 60 min. MO adsorption kinetic data by AlgN and AlgN-CTAB tended to take the kinetic model of pseudo-second-order (PSO) with PSO rate constant ( k 2 ) values of 0.56 and 2.17 g mg-1 min-1, serially. The MO adsorption isotherm pattern by AlgN tends to take the Freundlich adsorption isotherm, whereas in AlgN-CTAB it follows the Langmuir and Dubinin-Radushkevich adsorption isotherms. The results of the adsorption-desorption of MO by AlgN-CTAB with 4 repetition cycles resulted in % removal of MO > 80 % . The AlgN-CTAB adsorbent can be used repeatedly and is very effective in absorbing MO in water.


2021 ◽  
Vol 15 (3) ◽  
pp. 377-388
Author(s):  
Sadek Chentouf ◽  
◽  
Smail Kacha ◽  
Réda Marouf ◽  
Fouad Mekhalef Benhafsa ◽  
...  

Synthesis, characterization and application of the polyaniline-diatomite (PAD) composite in the adsorption of Reactive Red 120 (RR 120) and Acid Blue (AB) dyes were carried out. The composite was prepared by the in situ polymerization of aniline. Mass of purified diatomite was mixed with a solution containing aniline dissolved in 2M hydrochloric acid at room temperature. The solid obtained was characterized using the SEM, XRD and FTIR analyses. The kinetic adsorption of dyes was described using the pseudo-second order kinetic model. The adsorption isotherm of the RR 120 dye can be fitted by the Freundlich adsorption isotherm model. However, the adsorption isotherm of the AB dye can be better fitted by the BET model.


2021 ◽  
Vol 1 (2) ◽  
pp. 117-128
Author(s):  
Afrida Nurain ◽  
Protima Sarker ◽  
Md. Shiblur Rahaman ◽  
Md. Mostafizur Rahman ◽  
Md. Khabir Uddin

Biosorption is a convenient process for heavy metal remediation. In this study, banana peel was experimented to eliminate lead (Pb2+) from an aqueous solution following batch experiments. The functional groups of banana peel were identified by Fourier-transform infrared spectroscopy (FTIR). The adsorption mechanism was studied by the Langmuir and Freundlich adsorption isotherm model and determined the separation factor from the Langmuir adsorption isotherm. The adsorption of Pb2+ on dried banana peel had been studied at different adsorbent doses, pH, initial concentration of Pb, contact time, temperature, and agitation speed. After adsorption, Pb2+ was measured using atomic absorption spectroscopy (AAS). Maximum adsorption had taken place at pH 5 for adsorbent dose 45 g L-1. The optimum contact time and agitation speed was 30 minutes and 150 rpm, respectively for the initial Pb concentration of 100 ppm at 25°C. Both, Langmuir and Freundlich adsorption isotherm models shows the best fitting (r2 = 0.9978 and 0.9595) for Pb2+ adsorption. The maximum Pb2+ adsorption capacity was 2.1 mg g-1. The findings indicate that the banana peel waste could be a potential adsorbent for heavy metal removal. Moreover, the waste management problem could be solved in an eco-friendly manner by utilizing it for the eradication of Pb2+ from wastewater.


2021 ◽  
Vol 5 (2) ◽  
pp. 621-634
Author(s):  
Abdulfatai A. Siaka ◽  
Sunday O. Owa ◽  
M. K. Gafar ◽  
J. O. Okunola

The corrosion inhibition potential of lannea acida (LA) ethanol leaves extract was investigated using mild steel in 1.0 M HCl solution. The leaves extract was characterized using FT- IR Spectroscopy. The surface analysis of the mild steel was also studied using scanning electron microscopy. The study was carried out at an ambient temperature and selected high temperatures. The LA leaves extract concentration ranges from 0.1- 0.9g/L. The data obtained from weight loss measurements show that the leaves extract repressed the corrosion rate of mild steel. The increase in temperature with a corresponding increase or decrease in the inhibitor efficiency of LA leaves extract shows that the adsorption mechanism obeyed comprehensive adsorption. The value of activation energies (Ea) obtained which ranged from 15.32 to 17.63 kJ mol-1 agrees with the physical adsorption mechanism. The values of enthalpy of activation (ΔH*) obtained were positive and ranged from 38.29 to 59.00 KJ mol-1 is an indication that the dissolution of the mild steel is an endothermic reaction and requires less energy in the presence of LA leaves extract. The values of entropy of activation (ΔS*) obtained which were negative indicate that the activated complex in the rate-determining step is associative rather than dissociative. The kinetics study shows the adsorption process follows first-order kinetics. The adsorption isotherm data fitted best into Freundlich adsorption isotherm


2021 ◽  
Vol 9 (2) ◽  
pp. 54-64
Author(s):  
Lalmalsawm dawngliani ◽  
◽  
Gospel Lallawmzuali ◽  
Samuel Lallianrawna ◽  
Thanhming liana ◽  
...  

IMO compost was obtained using Indigenous Microorganisms (IMO) as inoculant through anaerobic fermentation process from kitchen waste biomass. The Physico-chemical analysis of the solid was obtained by taking pH, MC, OM, OC, N, K and P content. The biosorbent material was further characterized by SEM, IR and BET analytical techniques. Various physico-chemical parametric studies viz. effect of pH, initial dye concentration and background electrolyte concentrations are performed in the removal of Congo red (CR) dye using the IMO compost. The lower pH condition pH < 6.0 favoured the removal of Congo red and the percent removal was decreased with increase in the CR concentration. The removal of Congo red followed the pseudo-second order rate kinetics and the equilibrium state sorption data was reasonably fitted well to the Freundlich adsorption isotherm. In addition, the minimal effect of background electrolyte concentrations (0.0001 to 0.1 mol/L NaNO3) in the removal of CR inferred a specific sorption of Congo red forming ‘inner sphere’ complexes at the surface of the biosorbent.


2021 ◽  
Vol 9 (2) ◽  
pp. 161-168
Author(s):  
Ralte Malsawmdawngzela ◽  
◽  
Thanhming liana ◽  
Diwakar Tiwari ◽  
◽  
...  

The aim of this communication is to assess the sorption behavior of silanes grafted bentonite composite materials for Rhodamine B (RhB) from aqueous solution. The nanocomposites were synthesized by functionalization of the bentonite with 3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane under inert atmosphere. The batch experimental data indicated that the composite materials showed high percentage removal of RhB over a wide pH range, i.e., pH ~4.0 to 10.0. A high percentage removal of RhB was achieved within the concentrations studied from 1.0 to 25.0 mgL-1. Langmuir and Freundlich adsorption isotherm were obtained using equilibrium state sorption data. The equilibrium sorption was attained within 180 min of contact and the kinetic model best fitted the pseudo-second-order model. Further, the change in background electrolyte (NaCl) concentrations from 0.0001 to 0.1molL-1 NaCl and the presence of co-existing ions do not significantly affect the sorption of RhB by the composite sorbents except for EDTA.


2021 ◽  
Author(s):  
CI Chemistry International

In view of promising adsorption efficiency of clay based materials, a modified iron-kaolin clay was used as an adsorbent of Pb(II) and Cd(II) ions from aqueous solutions. The effects of various experimental parameters, such as initial metal ions concentration, contact time, temperature and pH were investigated. The Langmuir and Freundlich adsorption isotherm models were applied to the experimental equilibrium data at different temperatures. The maximum adsorption capacities of Pb(II) and Cd(II) ions were 76.92 and 75.19 (mg/g), respectively. Thermodynamic parameters such as the change of Gibbs free energy, enthalpy and entropy of adsorption were also calculated and it was found that the lead and cadmium ions uptake by modified kaolin clay is endothermic and spontaneous in nature.


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