Isotherm
The Kinetic Study of Adsorption of Copper Metal Ion in Selected Contaminated Red Soil Samples in Palestine
Thu, 2015-08-20 13:00 — Ahmad A. Abu-ObaidHeavy metals are persistent pollutants in the environment. Problems associated with the cleanup of sites contaminated by metals have demonstrated the need to develop remediation technologies that are feasible, quick, and effective in a wide range of physical settings. In this study we have investigated the adsorption of Cu (II), onto red soil in single and multi-element systems as a function of soil and heavy metal concentrations. Before contamination, soils were characterized to determine particle size, pH, organic matter ...
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Biosorption of Cd(II), Cr(III), and Cr(VI) by Saltbush (Atriplex Canescens) Biomass: Thermodynamic and Isotherm Studies
Tue, 2015-02-10 15:08 — Maather SawalhaThe biosorption data of Cd(II), Cr(III), and Cr(VI) by saltbush leaves biomass were fit on the Freundlich and Langmuir adsorption isotherms at 297 K. The Cd(II) and Cr(III) solutions were adjusted to pH 5.0 and the Cr(VI) solution was adjusted to pH 2.0. The correlation coefficient values indicated that the data fit better the Freundlich model. The maximal capacities (KF) were found to be 5.79×10−2, 3.25×10−2, and1.14×10−2 mol/g for Cr(III), Cd(II), and Cr(VI), respectively. Similar results were obtained using the Langmuir and the Dubinin–Radushkevick equations. Thermodynamic parameters calculated from the Khan and Singh equation and from the qe vs Ce plot show that the equilibrium constants for the biosorption of the metals follow the same order of the maximal capacities. The negative Gibbs free energy values obtained for Cd(II) and Cr(III) indicated that these ions were biosorbed spontaneously. The mean free energy values calculated from the Dubinin–Radushkevick equation (10.78, 9.45, and 9.05 for Cr(III), Cr(VI), and Cd(II), respectively) suggest that the binding of Cd(II), Cr(III), and Cr(VI) by saltbush leaves biomass occurs through an ionic exchange mechanism.
Adsorption of Diclofenac From Aqueous Solution Using Cyclamen Persicum Tubers based Activated Carbon (CTAC)
Mon, 2015-01-12 14:35 — Shehdeh JodehThis study aims to use the tissues of Cyclamen persicum
tubers to prepare activated carbon (CTAC) by different methods then to set up a
thermodynamic study of the pharmaceutical diclofenac sodium (DCF) adsorption
from aqueous solution onto this activated carbon. Optimum percent of DCF
removal was 72 % when CTAC dosage was 0.25 g and DCF concentration 50 mg/L.
Percentage removal of DCF increases when the concentration of DCF increases as
the maximum percentage removal reached 81 % when DCF concentration was 70 mg/L
and 0.7 g CTAC and pH ranging from 6 to 2.
Freundlich model describes efficiently adsorption isotherm of DCF onto CTAC
with n equal to 1.398 which value indicates a favorable adsorption. This
finding validates the assumption of multilayer physical adsorption process of
DCF. The results showed that DCF was physically adsorbed onto CTAC, as
confirmed by the values of ΔH° minor than 40 Kj/ mol. As ΔG° had negative
charge, the adsorption process is exothermic, and the adsorption process of the
DCF onto CTAC is spontaneous, depending on temperature.
Understanding Complexation and Desorption of Copper Ion in Three Contaminated Soil Types in Palestine Using Series of Different Surfactants and Ligands
Sun, 2013-03-03 14:38 — Ahmad A. Abu-ObaidThe Study of Kinetics and Thermodynamics of Selected Pharmaceuticals and Personel Care Products on Agriculture Soil
Wed, 2013-02-13 21:33 — Shehdeh JodehPollution of the aquatic environment by human and veterinary waste pharmaceuticals is an increasing area of concern but little is known about their ecotoxicological effects on wildlife. In this study, three pharmaceuticals were selected (ibuprofen, amoxicillin and caffeine) as examples that are released in the environment. All of them are marketed in the Palestinian market (Pharmacies), private clinics and hospitals. The adsorption of the selected pharmaceuticals was examined by batch sorption experiments onto agriculture soil. Pharmaceuticals adsorption kinetics followed the pseudo-second-order adsorption model. Adsorption isotherms were best fitted by the Freundlich isotherm model. The “n” parameters were higher than 1 and the Kf values for all of them were less than 1. High removal rates of amoxicillin and ibuprofen were achieved in acidic media (pH = 1-4) and reached more than 88% Except for the caffeine increased at higher pH and reached more than 92%. The thermodynamics parameters showed that the adsorption process on soil was spontaneous and exothermic.
Understanding Complexation and Desorption of Copper Ion in Three Contaminated Soil Types in Palestine Using Series of Different Surfactants and Ligands
Mon, 2012-12-24 13:08 — Shehdeh Jodeh
