Showing papers on "Langmuir published in 2007"
TL;DR: Kinetic parameters; rate constants, equilibrium adsorption capacities and related coefficients for each kinetic model were evaluated according to relative errors and correlation coefficients and results show that best fitted kinetic models are obtained to be in the order: the pseudo-first order, the Pseudo-second order and Elovich equations.
889 citations
TL;DR: Adsorption isotherms modeling shows that the interaction of phenolic compounds with activated carbon surface is localized monolayer adsorption, which correlates well with respective increase in molecular weight, cross-sectional area, and hydrophobicity and decrease in solubility and pKa.
881 citations
TL;DR: Kinetic study showed that the adsorption of dye on coir pith carbon was a gradual process and pH effect and desorption studies suggest that chemisorption might be the major mode of the Adsorption process.
868 citations
TL;DR: In this article, a batch sorption experiment was carried out for the removal of C.I. Basic Green 4 (Malachite Green), a cationic dye from its aqueous solution using cyclodextrin-based material (CD/CMC material) as adsorbent.
866 citations
TL;DR: Oak bark out-performed the other chars and nearly mimicked Calgon F-400 adsorption for lead and cadmium, and the oak bark char's ability to remove Pb(II) and Cd( II) is remarkable when considered in terms of the amount of metal adsorbed per unit surface area.
861 citations
TL;DR: The batch adsorption rate for the five systems indicated that the adsorptive mechanism was predominantly intraparticle diffusion but there was also a dependence on pore size as the dye diffuses through macropore, mesopore and micropore respectively.
806 citations
TL;DR: In this article, the adsorption of copper and lead ions onto tea waste from aqueous solutions was studied to enable comparison with alternative commonly available absorbents, and the equilibrium data were satisfactorily fitted to Langmuir and Freundlich isotherms.
767 citations
TL;DR: The results demonstrate that the adsorption process was spontaneous and endothermic under natural conditions.
735 citations
TL;DR: In this paper, an abundant agricultural byproduct in Malaysia, was used to prepare activated carbon by physiochemical activation method, and the adsorption capacity was found to increase with increase in the three parameters studied.
717 citations
TL;DR: In this article, the results of the best-fit model of the Langmuir and Freundlich models of adsorption were calculated and the results are discussed and the dimensionless factor, R L revealed the favorable nature of the isotherm of the dye-activated carbon system.
637 citations
TL;DR: In this article, a series of hypercrosslinked polymer networks has been synthesized by self-condensation of bischloromethyl monomers such as dichloroxylene (DCX), 4,4‘-bis(chlorometHyl)-1,1'biphenyl (BCMBP), and 9,10-bis (chloromethemyl)anthracene (BCMA), and these materials are predominantly microporous and exhibit Brunauer−Emmett−Teller (BET) surface areas of up to 1904 m2
Abstract: A series of hypercrosslinked polymer networks has been synthesized by the self-condensation of bischloromethyl monomers such as dichloroxylene (DCX), 4,4‘-bis(chloromethyl)-1,1‘-biphenyl (BCMBP), and 9,10-bis(chloromethyl)anthracene (BCMA). These materials are predominantly microporous and exhibit Brunauer−Emmett−Teller (BET) surface areas of up to 1904 m2/g as measured by N2 adsorption at 77.3 K (Langmuir surface area = 2992 m2/g). Networks based on BCMBP exhibit a gravimetric storage capacity of 3.68 wt % at 15 bar and 77.3 K, the highest yet reported for an organic polymer. The micro- and mesostructure of the networks is explained by a combination of solid-state NMR, gas sorption measurements, pycnometry, and molecular simulations. The isosteric heat of sorption for H2 on these materials is found to be in the range 6−7.5 kJ/mol. A molecular model is presented for a p-DCX network that simulates well certain key physical properties such as pore volume, pore width, absolute density, and bulk density. This...
TL;DR: The use of orange wastes, generated in the orange juice industry, for removing cadmium from aqueous solutions has been investigated and a strong dependence of the adsorption capacity on pH was observed, the capacity increasing as pH value rose.
TL;DR: In this article, the removal of Cr(VI) from aqueous solution by batch adsorption technique using different low-cost adsorbents was investigated, and the effect of pH, adsorbent type and concentration, initial Cr (VI) concentration and contact time on the selectivity and sensitivity of the removal process was investigated.
TL;DR: A significant decrease in the COD values was observed, which clearly indicates that both photocatalytic and adsorption methods offer good potential to remove Rhodamine B from industrial effluents.
TL;DR: DeltaH degrees, DeltaG degrees and E(a) all suggested that the adsorption of Procion Red MX-5B onto CNTs was by physisorption, more accurately represented by a pseudo second-order model.
TL;DR: In this article, the removal of acid green 25 (AG25) dye onto activated palm ash from aqueous solutions was investigated using Langmuir and Freundlich models.
TL;DR: The results showed that studied adsorbents can be an attractive low cost alternative for the treatment of wastewaters in batched or stirred mode reactors containing lower concentrations of chromium.
TL;DR: In this article, a cost effective biosorbent and the biosorption process involved in the adsorption of heavy metal-contaminated industrial wastewater using the developed bio-sorbent was studied.
TL;DR: In this paper, the effect of solution ionic strength on the uptake of Congo red dye by two different mesoporous carbons was also investigated, and the equilibrium adsorption data were interpreted using Langmuir and Freundlich models.
TL;DR: A novel magnetic nano-adsorbent was developed by treating Fe(3)O(4) nanoparticles with gum arabic to remove copper ions from aqueous solutions and the adsorption capacities for both MNP and GA-MNP increased with increasing the solution pH.
TL;DR: It is found that over the entire concentration range the adsorption on Bottom Ash takes place via particle diffusion process, while that of De-Oiled Soya undergoes via film diffusion process.
TL;DR: The calculated values for the heat of adsorption and the free energy indicate that adsorption of dyes is favored at low temperatures and the dyes are chemisorbed on activated charcoal.
TL;DR: It is concluded that natural clay can be used as an effective adsorbent for removing Cu(2+) and Zn(2+) from aqueous solutions.
TL;DR: The high negative value of change in Gibbs free energy (DeltaG0) indicates the feasible and spontaneous adsorption of BG on RHA, and Langmuir and R-P isotherms were found to best represent the data for BG advertisersorption onto RHA.
TL;DR: The Langmuir and Freundlich isotherm equations have been widely used for interpreting various adsorption processes as discussed by the authors, and many serious mistakes have been made in the literature in determination or calculation of thermodynamic parameters, especially in the determination of the change in the free energy of adorption.
Abstract: The Langmuir and Freundlich isotherm equations have been widely used for interpreting various adsorption processes. There are, however, many serious mistakes in the literature in determination or calculation of thermodynamic parameters, especially in the determination of the change in the free energy of adsorption using Langmuir, Freundlich and Henry constants. Many authors used these constants for the determination of ∆G expressed instead of dimensionless in some concentration units (for example: l mol-1, l g-1, ml mg-1, etc.).
TL;DR: Kinetic data correlated well with the pseudo-second-order kinetic model, indicating that the chemical sorption was the rate-limiting step and the thermodynamic study indicated that the adsorption process is spontaneous and exothermic in nature.
TL;DR: Batch adsorption of Methylene Blue and Acid Blue 25 onto ground hazelnut shells was studied in comparison with sawdust to explore the potential use of this material as low cost adsorbent for dye removal in dyehouse effluents.
TL;DR: Fluoride in drinking water above permissible levels is responsible for human and skeletal fluorosis and activated carbons prepared by one-step steam pyrolysis of rice straw were modified by liquid-phase oxidation using HNO3, H2O2 and KMnO4.
TL;DR: The comparative evaluation of the adsorption capacity of the modified sugarcane bagasse materials for Cu(2+), Cd( 2+), and Pb(2+) ions in aqueous single metal solution by classical titration.
TL;DR: Results of comparative adsorption capacity of both carbons indicate that groundnut shell can be used as a low-cost alternative to commercial powdered activated carbon in aqueous solution for dye removal.