Understanding the fundamentals of arsenic adsorption and oxidation reactions is critical for predicting its transport dynamics in groundwater systems. We completed batch experiments to study the interactions of arsenic with a common MnO2(s) mineral, pyrolusite. The reaction kinetics and adsorption isotherm developed from the batch experiments were integrated into a scalable reactive transport m...

The measured dynamic surface tension of a water drop in air saturated by heptane vapor shows a sharp decrease from about 60 mN m−1 to 40 mN m−1, and less after a certain adsorption time. The observed adsorption kinetics is analyzed by a theoretical model based on multilayer adsorption of alkanes from the vapor phase at the water surface. The model assumes a dependence of the kinetic coefficient...

in this work, the adsorption of the anionic dye, congo red (cr), from aqueous solution by using tea waste (tw) has been carried out at 30 °c. the equilibrium sorption isotherms and kinetics were investigated. the equilibrium adsorption was studied by the langmuir and freundlich models of adsorption. the experimental results manifested that the langmuir isotherm was the best model for the adsorp...

Zeolitic tuffs are found in different parts of the world. Iranian zeolite is a low-cost material that can be frequently found in nature. Surfactant-modified zeolite (SMZ) can be used for the adsorption of natural organic matter (NOM) from aqueous solutions. The adsorption study was conducted to evaluate the adsorption capacity of SMZ; furthermore, the effects of contact time, initial pH, and th...

The mechanism, isotherms and kinetics of removal of two endocrine disrupting chemicals, 17β-estradiol (E2) and 17αethinyloestradiol (EE2) by activated carbon adsorption were investigated in an agitated non-flow batch adsorption studies. Mathematical models were used to describe the adsorption phenomenon with the kinetic and thermodynamic parameters evaluated using the adsorption equilibrium dat...

The purpose of this study was to investigate the adsorption of uranium (VI) ions on the polypyrrole adsorbent. Polypyrrole was synthesized by a chemical method using polyethylene glycol, sodium dodecylbenzenesulfonate, and cetyltrimethylammonium bromide as the surfactant and iron (III) chloride as an oxidant in the aqueous solution. The effect of various surfactants on the synthesized polymers ...

Removal of Pb 2+ from aqueous solutions using coconut shell carbons produced by KOH activation is performed in this paper. Morphology and pore structure characteristic of coconut shell carbons are analyzed by SEM and nitrogen adsorption techniques. Effects of adsorbent concentration, agitation time and initial ion concentration on the adsorption behavior are investigated, and adsorption isother...

The adsorption of contaminants plays an important role in the process of their elimination from a polluted environment. This work describes the issue of loading environment with lead Pb(II) and the resulting negative impact it has on plants and living organisms. It also focuses on bentonite as a natural adsorbent and on the adsorption process of Pb(II) ions on the mixture of bentonite and botto...

   In the present study, CeO2/Fe2O3 nanocomposite was prepared by co-precipitation method and its application was investigated for arsenic removal from water. Characterization of the nano sized adsorbent particles was carried out using SEM and XRD techniques. Systemic adsorption experiments were performed in batch systems and the optimum conditions were obtained. The effects of p...

The rates of adsorption of three commercial reactive dyes and Cu(II) from water in the absence and presence of complexing agents using chitosan were measured at 308C. Three simplified kinetic models, i.e., pseudo-first-order, pseudo-second-order, and intraparticle diffusion, were tested to investigate the adsorption mechanisms. It was shown that the adsorption of reactive dyes and Cu(II) in the...