Showing papers on "Freundlich equation published in 2011"
TL;DR: In this article, rice husk treated with NaOH was used as a low cost adsorbent for the removal of malachite green from aqueous solution in batch adsorption procedure.
815 citations
TL;DR: Thermodynamic study showed that the adsorption was a spontaneous and exothermic process and kinetics followed a pseudo-second-order equation.
706 citations
TL;DR: It was found out that kinetics of adsorption varies with initial concentration of heavy metal ions, so CNT sheets have good potential application in environmental protection.
617 citations
TL;DR: A mesoporous carbon developed from waste tire rubber was used as an adsorbent for the removal and recovery of a hazardous azo dye, Acid Blue 113 and Kinetic studies indicated that the adsorption process follow first order kinetics and particle diffusion mechanisms are operative.
613 citations
TL;DR: In this article, a simple one-step solvothermal strategy using non-toxic and cost-effective precursors has been developed to prepare magnetite/reduced graphene oxide (MRGO) nanocomposites for removal of dye pollutants.
Abstract: A simple one step solvothermal strategy using non-toxic and cost-effective precursors has been developed to prepare magnetite/reduced graphene oxide (MRGO) nanocomposites for removal of dye pollutants. Taking advantage of the combined benefits of graphene and magnetic nanoparticles, these MRGO nanocomposites exhibit excellent removal efficiency (over 91% for rhodamine B and over 94% for malachite green) and rapid separation from aqueous solution by an external magnetic field. Interestingly, the performance of the MRGO composites is strongly dependent on both the loading of Fe3O4 and the pH value. In addition, the adsorption behavior of this new adsorbent fits well with the Freundlich isotherm and the pseudo-second-order kinetic model. In further applications, real samples—including industrial waste water and lake water—have been treated using the MRGO composites. All the results demonstrate that the MRGO composites are effective adsorbents for removal of dye pollutants and thus could provide a new platform for dye decontamination.
581 citations
TL;DR: The results suggest that biochar converted from anaerobically digested sugar beet tailings is a promising alternative adsorbent, which can be used to reclaim phosphate from water or reduce phosphate leaching from fertilized soils.
504 citations
TL;DR: In this paper, the authors measured the properties of activated carbons (ACs) of coconut shell produced by NaOH activation at impregnation ratios of NaOH:char (w/w) equal to 1:1, 2:1 and 3:1 (AC-3) and found that AC-3 has a high surface area and showed to be an efficient adsorbent for removal of methylene blue (MB) from aqueous solutions.
494 citations
TL;DR: FTIR demonstrated that carboxyl and hydroxyl groups were involved in the biosorption of the metal ions in the grafted copolymerization-modified orange peel.
493 citations
TL;DR: It is remarkable that oak chars can remove similar amounts of Cr(VI) as activated carbon (S(BET): ∼ 1000 m(2)g(-1)).
455 citations
TL;DR: In this article, the adsorption characteristics of phenol from water onto zeolite were studied, i.e., kinetics, mechanism, isotherms, and thermodynamics.
448 citations
TL;DR: In this paper, the adsorption of methylene blue (MB) onto activated carbon produced from flamboyant pods (Delonix regia ) and obtained under optimized conditions (AC op ) was carried out.
TL;DR: In this paper, the adsorption of methyl orange onto multiwalled carbon nanotubes (MWCNTs) from aqueous solutions was studied, in which the influence of contact time, dosage, temperature, pH, and methyl orange concentration in the solution were investigated.
TL;DR: In this paper, the effect of pH, initial concentration of lead(II) ions, contact time, and adsorbent dosage on the adsorption was studied in a batch process mode.
TL;DR: In this article, the effect of operational parameters such as adsorbent dosage, dye concentration, inorganic anion (salt), pH and temperature onto dye removal was studied.
TL;DR: In this paper, the authors investigated the biosorption of Cu(II) and Cr(III) ions from aqueous solutions by peanut shell biomass as a function of initial pH, initial biomass concentration and temperature.
TL;DR: In this paper, a mesoporous silica with amine (NH 2 ) and melamine-based dendrimer amines (MDA)-SBA-15 was used as an adsorbent for the removal of metal ions from aqueous solution.
TL;DR: In this article, a single-stage batch absorber design for the methylene blue adsorption onto pine cone biomass has been presented based on the Langmuir isotherm model equation.
Abstract: The kinetics and mechanism of methylene blue adsorption onto raw pine cone biomass (Pinus radiata) was investigated under various physicochemical parameters. The extent of the methylene blue dye adsorption increased with increases in initial dye concentration, contact time and solution pH but decreases with the amount of adsorbent, salt concentration and temperature of the system. Overall the kinetic studies showed that the methylene blue adsorption process followed pseudo-second-order kinetics among various kinetic models tested. The different kinetic parameters including rate constant, half-adsorption time and diffusion coefficient are determined at different physicochemical conditions. Equilibrium data were best represented by Langmuir isotherm among Langmuir and Freundlich adsorption isotherm. The maximum monolayer adsorption capacity of pine cone biomass was 109.89 mg/g at 30°C. The value of separation factor, R
L, from Langmuir equation and Freundlich constant, n, both give an indication of favourable adsorption. Thermodynamic parameters such as standard Gibbs free energy (∆G
0), standard enthalpy (∆H
0), standard entropy (∆S
0) and the activation energy (A) were calculated. A single-stage batch absorber design for the methylene blue adsorption onto pine cone biomass has been presented based on the Langmuir isotherm model equation.
TL;DR: The as-prepared Ni(OH)(2) and NiO nanosheets are found to be effective adsorbents for the removal of Congo red pollutant from wastewater as a result of their unique hierarchical porous structures and high specific surface areas.
TL;DR: In this article, the comparative and competitive adsorption of Cu(II, Ni(II), and Pb(II) from aqueous solution using chitosan immobilized on bentonite (CHB) was investigated.
TL;DR: In this article, the ability of palm kernel fiber (PKF) to adsorb methylene blue (MB) and crystal violet (CV) from aqueous solutions has been studied.
TL;DR: According to the experimental results, activated carbon prepared from tobacco residue seems to be an effective, low-cost and alternative adsorbent precursor for the removal of phenol from aqueous solutions.
TL;DR: In this article, the adsorption behavior of some low-cost adsorbents such as peanut husk charcoal, fly ash, and natural zeolite, with respect to Cu 2+, and Zn 2+ ions, has been studied in order to consider its application to the purification of metal finishing wastewater.
TL;DR: Magnetic and non-magnetic low cost activated carbons from almond shells were prepared, characterized, and used to remove 2,4,6-trinitrophenol (TNP) from water as discussed by the authors.
TL;DR: In this paper, the authors compared the performance of three types of adsorbents for removing methylene blue (MB) from aqueous solutions: cotton stalk (CS), sulphuric acid treated cotton stalks (SCS) and phosphoric acid-treated cotton stinger (PCS).
TL;DR: It was found that the nitric acid treatment of samples has a detrimental effect in adsorption capacity, whereas thermal treatments, especially at 900 °C after oxidation, enhance adsorptive performance.
TL;DR: In this paper, the adsorption behavior of nickel (II) from aqueous solution onto agricultural waste such as cashew nut shell (CNS) was investigated as a function of parameters such as solution pH, CNS dose, contact time, initial nickel(II) concentration and temperature.
TL;DR: In this article, the potential of lotus leaf for the removal of methylene blue (MB) from aqueous solution was investigated and the results of analysis indicated that the equilibrium data were perfectly represented by Koble-Corrigan isotherm.
TL;DR: In this article, two pillared clays are synthesized by intercalation of solutions of aluminium and zirconium and evaluated as adsorbents for the removal of Orange II and Methylene Blue from aqueous solutions.
TL;DR: In this article, the multiwalled carbon nanotube has been used as an efficient adsorbent for the removal of Alizarin red S (ARS) and morin from wastewater.
Abstract: The multiwalled carbon nanotube has been used as an efficient adsorbent for the removal of Alizarin red S (ARS) and morin from wastewater. The influence of variables including pH, temperature, concentration of the dye, amount of adsorbents and contact time, and so forth on the removal of both dyes was investigated by the batch method. Graphical correlations of various adsorption isotherm models like Langmuir, Freundlich, Tempkin, and Dubinin−Radushkevich have been carried out. The adsorption of ARS and morin has been found to be endothermic and feasible in nature. Various thermodynamic parameters, such as Gibbs free energy, entropy, and enthalpy, of the ongoing adsorption process have been calculated. The kinetic studies suggest the process following pseudosecond-order kinetics and involvement of the particle-diffusion mechanism.
TL;DR: The results revealed that nanoparticle impregnated onto tea waste from agriculture biomass, can be an attractive option for metal removal from industrial effluent.