adsorption

Selective Removal of Mercury(II) Using Hydrogels Prepared by Gamma Radiation

To selectively remove mercury(II), 2-hydroxyethyl methacrylate (HM) and 2-hydroxyethyl methacrylate/acrylamide (HM/ACR) hydrogels were synthesized using radiation. These hydrogels were used in swelling, diffusion, and binding studies. Swelling parameters for HM/ACR−Hg2+ system are higher than those of HM−Hg2+ systems. Binding of Hg2+ has been observed to be C-type for HM and L-type for HM/ACR hydrogels. Binding parameters were calculated using Freundlich, Langmuir and Henry models.

STATICS OF ADSORPTION OF ANIONIC SURFACTANTS

The paper presents the results of the study of the statics of adsorption of surface-active substances from model solutions by activated carbon and zeolite. The results of photometric determination of the concentration of anionic surfactants before and after adsorption are presented. The results of adsorption capacity calculations are presented. The experimental results using the program (Langmuir 1.03) were numerically calculated. Sorption isotherms of sodium dodecyl sulfate indicate the mechanism of monomolecular physical adsorption.

Dynamics of Adsorption of Copper Ions in Fixed-Bed Column and Mathematical Interpretation of the First Stage of the Process

The dynamics of the adsorption process in the fixed-bed column was experimentally studied on the example of the system natural zeolite - water solution of copper salt with low concentrations, which are characteristic for wastewater treatment processes from toxic contaminants. The initial curves of the adsorption process for the height of the sorbent layer of 5 and 7 cm were constructed. The equilibrium of such processes can be described by Henry's linear equation. The adsorption process in the layer consists of two stages, which are examined in the study.

Synthesized Copolymer Derivative of Poly(Styrene-alt-Maleic Anhydride) as a New Chelating Resin to Remove Heavy Metal Ions from Aqueous Solution

Chelating resin as a new copolymer for metal ions removal was prepared using 3-(4-hydroxyphenyl) cyclopropane-1,1,2,2-tetracarboxylic acid and 1,2-diaminoethane on the poly(styrene-alt-maleic anhydride). Parameters of sorption behavior were investigated under various conditions. Kinetics studies revealed that the adsorption process confirmed the pseudo-second-order kinetics and adsorption data were well fitted to Langmuir isotherm. 

Adsorption Kinetics and Isotherms of Cu(II) and Fe(II) Ions from Aqueous Solutions by Fly Ash-Based Geopolymer

This paper describes the adsorption of Cu2+ and Fe2+ ions, common heavy metals found in industrial wastewater, by a fly ash-based geopolymer in batch adsorption experiments. Kinetics studies showed that the adsorption of each ion followed a pseudo-second order reaction. Moreover, adsorption isotherm of Cu2+ and Fe2+ ions followed the Langmuir model. Monolayer adsorption capacities were approximately 53.76 mg/g for Cu2+ ion and 52.63 mg/g for Fe2+ ion, respectively.

Adsorption of Cationic and Anionic Dyes from Aqueous Solution Using Sunflower Husk

The current study deals with the removal of cationic dye (brilliant green) and anionic dye (methyl orange) from wastewater by using sunflower husk as an adsorbent. The operation takes place batch wise by applying several concentrations of the dye solution with various adsorbent amounts, at a range of initial PH values and particle sizes at varying contact time intervals. The percent of dye removed for two dyes increased with increasing time and adsorbent dose and decreased with increasing the dye concentration and particle size. The equilibrium time differed according to conditions used.

Superhigh Adsorption of Cadmium(II) Ions onto Surface Modified Nano Zerovalent Iron Composite (CNS-nZVI): Characterization, Adsorption Kinetics and Isotherm Studies

The efficiency of surface modified nanoscale zerovalent iron (nZVI) composite by cashew nut shell (CNS) was tested for the removal of cadmium ions from the aqueous solutions. 2 g/l CNS-nZVI was efficient for 98% removal. The adsorption capacity was 35.58 mg/g. The Freundlich isotherm (R2 = 0.9769) and the pseudo-second order adsorption kinetics data fitted well. This proved CNS-nZVI has a high removal efficiency for Cd(II) from aqueous solutions.

Synthesis, Characterization and Application of a Diatomite-Based Composite for the Adsorption of Anionic Dyes in Aqueous Solutions

Synthesis, characterization and application of the polyaniline-diatomite (PAD) composite in the adsorption of Reactive Red 120 (RR 120) and Acid Blue (AB) dyes were carried out. The composite was prepared by the in situ polymerization of aniline. Mass of purified diatomite was mixed with a solution containing aniline dissolved in 2M hydrochloric acid at room temperature. The solid obtained was characterized using the SEM, XRD and FTIR analyses. The kinetic adsorption of dyes was described using the pseudo-second order kinetic model.

EXTRANEOUS DIFFUSION KINETICS OF AMMONIUM IONS ADSORPTION IN THE PRESENCE OF OTHER IONS

The article presents the results of the study of the kinetics of ions adsorption from multi-component mixtures. The isotherms of sorption of ammonium nitrogen in the presence of phosphates indicate a decrease in the exchange capacity of zeolite due to its competition for active absorption centres. This study was carried out with two ions of inorganic nature. In the presence of the third organic component in the solution (protein substance - albumin), the sorption capacity of zeolite decreases even more in comparison with ammonium ions.

INVESTIGATION OF THE PROCESS OF Fe (III) ADSORPTION BY METHODS OF MULTIDIMENSIONAL CLUSTER ANALYSIS

The results of the study of the adsorption capacity of a number of sorbents of natural and synthetic origin with respect to iron ions have been clustered. The sorption capacity of the following sorbents was studied: natural zeolite of the Sokyrnytsia deposit, synthetic sorbent based on the ash of Doborotvir heat power plant, Al2O3, SiO2, as well as some types of soils: sandy soil, black soil and clay. Equations describing the regularities of adsorption processes depending on the type of sorbent are obtained.