A detailed analysis of literature sources on the content of fluorides in the environment, methods of conditioning and defluoridation of water was held. The mechanism of interaction of fluorides with zeolite in the process of adsorption treatment of wastewaters and domestic waters was clarified. It was first established that in the process of adsorption there is the formation of magnesium fluoride compounds due to the binding of cations extracted from the zeolite by the mechanism of ion exchange.
Adsorption of nickel and chromium was investigated using fuller’s earth. The experimental data were analyzed using five 2-parameter adsorption models and three 3-parameter models. The maximum adsorption capacities for nickel and chromium were 769 and 556 mg/g, respectively. The Langmuir isotherm model was found to have the best fitting indicating monolayer adsorption. The adsorption was found to have an exothermic nature.
The aim of this research was to investigate the adsorption properties of anthraquinone modiﬁed carbon nanotube (ACNT) in oily wastewaters containing Pb ions. The modiﬁed adsorbents were characterized using Fourier transform infra-red spectroscopy and SEM analysis. The adsorption and regeneration studies were conducted in batch mode using a Taguchi (L16) orthogonal array to optimize experimental runs. The controllable factors used in this study consisted of: pH of the solution (A); adsorbent dosage (B); adsorbent type (C); contact time (D); temperature (F).
Oligomeric peroxide adsorption of sebacic acid on aerosil and magnesium oxide was studied. Adsorption process parameters were found. It is shown that the adsorption takes place through the hydrogen bonds formation between OH– groups of adsorbents surface and peroxide groups. The adsorption process suggests the behavior of peroxide compounds on the water-air phase’s interface. Monomolecular film formations on water surface for oligomeric peroxides were studied.
The present study is focused on the use of activated carbon derived from water hyacinth (WH-AC) as adsorbent for the removal of Cr(VI) from aqueous solution. The optimized WH-AC was found to be mesoporous and considered as granular. The surface area of 11.564 m2/g was found to have a good adsorption capacity. The adsorption data of the optimized WH-AC followed a pseudo-second order kinetics and the Freundlich isotherm model.
This work reveals a method of complex thermal and chemical activation of natural clinoptilolite from Sokyrnytsky deposit. The chemical activation of a mineral was carried out by HCl solutions treatment at various ratios of liquid-to-solid phases. With the use of thermal and infrared (IR) spectroscopic analyses, the adsorption property of a natural and activated clinoptilolite has been examined for water vapor. The ability of complexly activated clinoptilolite to adsorb direct dyes from their aqua solutions has been investigated.
The IR spectroscopy and complex thermal analysis have been used to analyze the adsorption capacity of Transcarpathian clinoptilolite, both naturally occurring and activated, relative to water vapor.
The results of the research of the adsorption capacity of a number of sorbents of natural and synthetic origin for ammonium ions have been clustered. The natural zeolite of the Sokyrnytsia deposit, a synthetic sorbent based on the fly ash of Dobrotvir state district heat power plant, Al2O3, SiO2, as well as some types of soil: sandy soil, black soil, and clay were used in the research. Equations describing the regularities of adsorption processes depending on the type of sorbent were obtained. According to the obtained dendrograms, two main clusters of sorbents were identified.
We consider a solution of nanoparticles in a pore with one of its walls being a liquid crystalline polymer brush. Both nanoparticles' ligands and the brush molecules side chains contain the same liquid crystalline groups. The system is studied using the molecular dynamics simulations. At both cases of a low and high brush density, the aggregation between the pairs of nanoparticles in a bulk and between the brush molecules prevail. However, we found a specific brush density when the nanoparticles are adsorbed more readily on a brush than aggregate in a bulk. A set of density profiles as
An alternative method of purification of aqueous sulfide-alkaline effluents from sulfide and hydrosulfide ions by their adsorption with mixed sorbents based on activated charcoal and kieselguhr has been investigated. High adsorption efficiency of mixed sorbents for purification of model sulfide- and hydrosulfide-containing solutions has been established. The dependence of the extraction degree of sulfide and hydrosulfide ions from aqueous solutions on their concentration, adsorption time and sorbent mass used has been investigated.