1. On the Theory of the Freundlich Adsorption Isotherm

1992 ◽  
pp. 58-67
Keyword(s):  
Adsorption Isotherm ◽  
Freundlich Adsorption Isotherm

scholarly journals Adsorption Study for Trifluralin on Iraqi ? –Alumina

2012 ◽  
Vol 9 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Adsorption Isotherm ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Adsorption Process ◽  
Kinetic Equations ◽  
Adsorption Study ◽  
Adsorption Capacities ◽  
Experimental Parameters ◽  
Freundlich Adsorption Isotherm ◽  
Equilibrium Adsorption Isotherm

Equilibrium adsorption isotherm for the removal of trifluralin from aqueous solutions using ? –alumina clay has been studied. The result shows that the isotherms were S3 according Giels classification. The effects of various experimental parameters such as contact time, adsorbent dosage, effect of pH and temperature of trifluralin on the adsorption capacities have been investigated. The adsorption isotherms were obtained by obeying freundlich adsorption isotherm with (R2 = 0.91249-0.8149). The thermodynamic parameters have been calculated by using the adsorption process at five different temperature, the values of ?H, ?G and ?S were (_1.0625) kj. mol-1, (7.628 - 7.831) kj.mol-1 and (_2.7966 - _2.9162) kg. k-1. mol-1 respectively. The kinetic study of adsorption process has been studied depending on three kinetic equations: 1- Allergen equation 2- Morris –weber eguation 3- Reichenberg eguation. In general, the result shows the isotherm were on ?- alumina according to Giels classification.? –alumina and thermodynamic

scholarly journals Adsorption Study for Chromium (VI) on Iraqi Bentonite

2010 ◽  
Vol 7 (1) ◽  
pp. 745-756
Author(s):  
Baghdad Science Journal
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Process ◽  
Kinetic Equations ◽  
Bentonite Clay ◽  
Sorption Process ◽  
Adsorption Study ◽  
Chromium Vi ◽  
Freundlich Adsorption Isotherm ◽  
Different Temperatures ◽  
The Subject

The subject of this research involves studying adsorption to remove hexavalent chromium Cr(VI) from aqueous solutions. Adsorption process on bentonite clay as adsorbent was used in the Cr(VI) concentration range (10-100) ppm at different temperatures (298, 303, 308 and 313)K, for different periods of time. The adsorption isotherms were obtained by obeying Langmuir and Freundlich adsorption isotherm with R2 (0.9921-0.9060) and (0.994-0.9998), respectively. The thermodynamic parameters were calculated by using the adsorption process at four different temperatures the values of ?H, ?G and ?S was [(+6.582 ? +6.547) kJ.mol-1, (-284.560 ? -343.070) kJ.mol-1 and (+0.977 ? +1.117) kJ.K-1.mol-1] respectively. This data indicates the spontaneous sorption process. The kinetic study of adsorption process was studied depending on three kinetic equations: 1- Lagergren equation 2- Morris-Weber equation 3- Reichenberg equation

The Derivation of Freundlich Adsorption Isotherm

Daxue Huaxue ◽  
2015 ◽  
Vol 30 (3) ◽  
pp. 76-79
Author(s):  
Shi Jibin ◽  
◽  
◽  
Liu Guojie
Keyword(s):  
Adsorption Isotherm ◽  
Freundlich Adsorption Isotherm

Experiment Study on Treatment of Chromium(VI)-Containing Groundwater by Modified Synthetic Zeolite

2012 ◽  
Vol 430-432 ◽  
pp. 1253-1256 ◽  
Author(s):  
Yu Jie Huang ◽  
Huan Zhen Zhang
Keyword(s):  
Adsorption Isotherm ◽  
Hexavalent Chromium ◽  
Treatment Effect ◽  
Synthetic Zeolite ◽  
Experiment Study ◽  
Ph Adjustment ◽  
Modified Zeolite ◽  
Solid Ratio ◽  
Chromium Vi ◽  
Freundlich Adsorption Isotherm

In order to improve the removal ability of hexavalent chromium on the synthetic zeolite, the synthetic zeolite was modified by FeSO4, which was used to removal hexavalent chromium in groundwater. The results showed that the concentration of Cr (VI) can be reduced from 5.0mg/l to 0.03 mg/l, which meets the requirements of groundwater standards (0.05mg/l) by using modified zeolite in a liquid-to-solid ratio of 20 ml/g, pH=3 for 120 minutes. The adsorption of Cr (VI) on the modified synthetic zeolite could be described by the Langmuir and Freundlich adsorption isotherm. It is showed that the synthetic zeolite modified by FeSO4 has good treatment effect and after treatment the pH of groundwater can reach around 6.8, which need no more pH adjustment.

On the fractality of the Freundlich adsorption isotherm in equilibrium and non-equilibrium cases

2016 ◽  
Vol 18 (30) ◽  
pp. 20784-20789 ◽  
Author(s):  
Przemysław Borys ◽  
Zbigniew J. Grzywna
Keyword(s):  
Adsorption Isotherm ◽  
Freundlich Isotherm ◽  
Fractal Properties ◽  
Freundlich Adsorption Isotherm ◽  
Isotherm Of Adsorption ◽  
Non Equilibrium

This work relates the fractal properties of the adsorbent to the exponent of the Freundlich Isotherm of adsorption.

scholarly journals Retention of phosphate by peat samples

1959 ◽  
Vol 31 (1) ◽  
pp. 215-225 ◽  
Author(s):  
Armi Kaila
Keyword(s):  
Adsorption Isotherm ◽  
Phosphorus Sorption ◽  
Natural Conditions ◽  
Peat Soils ◽  
Present Material ◽  
Sampling Depth ◽  
Soluble Iron ◽  
Volume Weight ◽  
Freundlich Adsorption Isotherm ◽  
Soluble Aluminum

The factors on which the retention of phosphorus by peat depends were studied on the basis of a material of 134 virgin peat samples. The coefficient k in the Freundlich adsorption isotherm y = kcn was used as an indicator of the phosphate sorption. The association of k with the sampling depth, the degree of decomposition, weight of volume, pH, extractable calcium, and the iron and aluminum dissolved by 0.1 N hydrochloric acid was treated. The acid-soluble aluminum gave with k a highly significant correlation which did not decrease when the effects of acid-soluble iron and the degree of humification were eliminated. The correlation between k and the acid-soluble iron was also highly significant although less close than the former association, and it was to some extent lowered by the elimination of the effect of aluminum. The fairly low, although statistically significant correlation between k and the degree of humification as expressed by the degree of decomposition or by the volume weight disappeared when the effect of aluminum was isolated. In the present material the sampling depth, pH and the content of extractable calcium did not give any significant correlation with k. As far as these results are valid under natural conditions, aluminum appears to play a more important role in the phosphorus sorption of peat soils than iron does.

scholarly journals Dye Anionic Removal From Water by Green Synthesized Nannochloropsis Sp.- Cetyltrimethylammonium Bromide Surfactant: Kinetics, Adsorption Isotherm and Adsorbent Regeneration

2021 ◽  
Author(s):  
Buhani . ◽  
Nurul Miftahza ◽  
Suharso . ◽  
Desy Permatasari ◽  
Sumadi .
Keyword(s):  
Adsorption Isotherm ◽  
Cetyltrimethylammonium Bromide ◽  
Analysis Data ◽  
Optimum Conditions ◽  
Adsorption Ability ◽  
X Ray ◽  
Adsorbent Regeneration ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order ◽  
Adsorption Desorption

Abstract 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). Biomass modification of Nannochloropsis sp. by CTAB has been successfully carried out through confirmation from the analysis data produced by Fourier-transform infrared spectroscopy and scanning electron microscope & energy-dispersive X-ray spectroscopy. 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 kinetics data by AlgN and AlgN-CTAB tended to take the kinetics model of pseudo-second-order (PSO) with PSO rate constant (k2) values of 0.56 and 2.17 g mg-1min-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-Raduskevich adsorption isotherms (AIML and AIMDR). The results of the adsorption-desorption of MO by AlgN-CTAB with 4 repetition cycles resulted % removal of MO > 80%. The AlgN-CTAB adsorbent can be used repeatedly and is very effective in absorbing MO in solution.

scholarly journals Improved Adsorption Capacity of Nannochloropsis sp. through Modification with Cetyltrimethylammonium Bromide on the Removal of Methyl Orange in Solution

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Buhani ◽  
Suharso ◽  
Nurul Miftahza ◽  
Desy Permatasari ◽  
Sumadi
Keyword(s):  
Methyl Orange ◽  
Adsorption Isotherm ◽  
Cetyltrimethylammonium Bromide ◽  
Analysis Data ◽  
Optimum Conditions ◽  
Adsorption Ability ◽  
X Ray ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order ◽  
Adsorption Desorption

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.

KINETICS AND ISOTHERM STUDIES OF Pb(II) IMPRINTED CARBOXYMETHYL CHITOSAN–PECTIN-PEGDE

2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Budi Hastuti ◽  
Dwi Siswanta ◽  
Mudasir Mudasir ◽  
Triyono Triyono
Keyword(s):  
Adsorption Isotherm ◽  
Kinetic Model ◽  
Metal Ion ◽  
Diglycidyl Ether ◽  
Carboxymethyl Chitosan ◽  
Second Order ◽  
Order Kinetic ◽  
Freundlich Adsorption Isotherm ◽  
Order Kinetic Model ◽  
Chelation Reaction

Pectin and chitosan are biomaterials that capable to act as biosorbent. Pectin has active groups, such as carboxyl, methoxyl, and hydroxyl (OH), while chitosan has amine group (–NH2) and hydroxyl (OH) as the active site metal ion absorber. Integration of two biopolymers is conducted by using a suitable cross-linker agents that are expected to form stable and more organized structure. This structure facilitate metal ions to enter and to form chelation reaction. Thus, it has great capacity for metal adsorption. A modified natural adsorbent pectin-chitosan has been synthesized by reacting of -OH group among pectin (Pec) and chitosan with Poly(ethylene glycol) Diglycidyl Ether (PEGDE) crosslinker agent to form a stable and an acidic medium-resistance adsorbent. Prior to increasing the active group of the adsorbent, chitosan was attached with acetate to form Carboxymethyl Chitosan (CMC). Furthermore, the CMC-Pec-PEGDE adsorbent was imprinted with Pb (II) to afford Pb(II) imprinted-CMC-Pec-PEGDE adsorbent in order to improve the selective sorption of Pb(II) metal ion. All of the functional groups attached on the synthesized adsorbents were characterized by Fourier Transform Infrared (FT-IR) Spectrometry. The kinetics and thermodynamics bath sorption of Pb(II) on Pb(II) imprinted-CMC-Pec-PEGDE film adsorbent have been investigated including the optimal condition for adsorption. The pseudo first-order and second-order kinetic model were investigated in order to determine the adsorption mechanism. The results indicated that all of the three adsorbent, CMC, CMC-Pec-PEGDE, and Pb(II) imprinted-CMC-Pec-PEGDE followed a pseudo-second-order kinetic model. Furthermore, adsorption studies of Pb(II) ion on CMC and CMC–Pec-PEGDE found to follow Langmuir adsorption while on imprinted-CMC-Pec-PEGDE followed Freundlich adsorption isotherm. The adsorption isotherm parameters of CMC and CMC-Pec-PEGDE adsorbents were ΔG° of 24.8 and 23.1 kJ mol-1, respectively. While Pb(II) imprinted-CMC-Pec-PEGDE followedisotherm model with ΔG° of 9.6 kJ mol-1.

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