Utilization of Modified Attapulgite for the Removal of Sr(II), Co(II), and Ni(II) Ions from Multicomponent System, Part I: Kinetic Studies.

Radionuclide sorption by natural and modified clays is extensively accepted to be an important process from the radioactive waste point of view. This work focused on modification of natural attapulgite with a layered double hydroxide to produce a novel chemisorbent for Sr, Ni, and Co removal from multicomponent solution. The structural and surface characteristics of both attapulgite (ATP) and modified attapulgite (LDH-ATP) were investigated using XRD, FTIR, SEM, and thermal analysis.

Correction to: Evaluation of hydroxyapatite/poly(acrylamide-acrylic acid) for sorptive removal of strontium ions from aqueous solution.

The original publication of this paper contains a mistake.

Evaluation of hydroxyapatite/poly(acrylamide-acrylic acid) for sorptive removal of strontium ions from aqueous solution.

A composite polymer, hydroxyapatite/poly(acrylamide-acrylic acid), was synthesized by gamma-induced polymerization. The factors affecting the sorption process were evaluated. The removal increased with time and achieved equilibrium after 1 h for all initial concentration ranges (10-50 mg/L).

Template polymerization synthesis of hydrogel and silica composite for sorption of some rare earth elements.

New sorbents containing 2-acrylamido 2-methyl propane sulphonic acid monomer onto poly(vinyl pyrilidone) P(VP-AMPS) hydrogel and P(VP-AMPS-SiO2) composite have been synthesized by radiation template polymerization. The effect of absorbed dose rate (kGy), crosslinker concentration and polymer/monomer ratio on the degree of template polymerization of P(VP-AMPS) hydrogel was studied. The degree of polymerization was evaluated by the calculated percent conversion and swelling degree.

Two-step method for preparation of NaA-X zeolite blend from fly ash for removal of cesium ions.

Pure zeolites can be synthesized from silica extracts obtained from fly ash by alkaline leaching. The extraction potential of industrial by-product fly ash was investigated under repeated fusion process conditions. The amount of extracted silica was 131.

Evaluation of zeolite A for the sorptive removal of Cs+ and Sr2+ ions from aqueous solutions using batch and fixed bed column operations.

Zeolite A was chemically synthesized and evaluated, as inorganic ion exchange material, for the removal of cesium and strontium ions from aqueous solutions in both batch and fixed bed column operations. Batch experiments were carried out as a function of pH, initial ion concentration and temperature. Simple kinetic and thermodynamic models have been applied to the rate and isotherm sorption data and the relevant kinetic and thermodynamic parameters were determined from the graphical presentation of these models.

Modeling the long-term leaching behavior of (137)Cs, (60)Co, and (152,154)Eu radionuclides from cement-clay matrices.

Leaching characteristics of some radionuclides that are commonly encountered in radioactive waste streams from immobilized waste matrices in different cement-clay grouts have been assessed to investigate the influence of the clay additives on the leaching behavior of the solid waste matrices. The International Atomic Energy's Agency (IAEA) standard leach method has been employed to study the leach pattern of (137)Cs, (60)Co, and (152,154)Eu radionuclides immobilized in ordinary Portland cement (OPC), OPC-bentonite, and OPC-red clay grouts. The examination of the leaching data revealed that adding clays to OPC reduces the leach pattern as OPC-bentonite View Article and Find Full Text PDF

Preparation and evaluation of cerium(IV) tungstate powder as inorganic exchanger in sorption of cobalt and europium ions from aqueous solutions.

Cerium(IV) tungstate powder was chemically synthesized and exploited as adsorbent material for the decontamination study of cobalt and europium ions from radioactive waste solutions under simulated conditions using batch technique. The influences of pH, particle size and temperature have been reported. The uptake of europium was found to be slightly greater than that of cobalt and the apparent sorption capacity increases with increase in temperature.

Immobilization of cesium and strontium radionuclides in zeolite-cement blends.

Zeolites are preferred ion exchange materials for the removal of radioisotopes from aqueous nuclear wastes because of their selectivity, radiation and temperature stability, and good compatibility with the cement matrix. Loaded materials, which are not regenerated, are preferably embedded in a solid matrix prior to ultimate storage in a repository. The aim of the present study is to investigate the possibility of solidifying exhausted synthetic zeolite A, loaded with (137)Cs and/or (90)Sr radionuclides, in Ordinary Portland Cement (OPC).

Modeling batch kinetics and thermodynamics of zinc and cadmium ions removal from waste solutions using synthetic zeolite A.

The sorptive removal of zinc and cadmium ions from aqueous solutions using synthetic zeolite A was investigated. Experiments were carried out as a function of solute concentration and temperature (298-333 K). Several kinetic models were used to test the experimental rate data and to examine the controlling mechanism of the sorption process.