Resorcinol-formaldehyde coated XAD resin beads for removal of cesium ions from radioactive waste: synthesis, sorption and kinetic studies

Abstract

A novel synthetic method was developed to synthesize resorcinol-formaldehyde (RF) resin in spherical form, of required mesh size, using XAD-4 as template beads. The synthesized RF-coated XAD (RF-XAD) beads were characterized, using different techniques. Suitable size and mechanical stability, along with their spherical shape, make these beads most appropriate for column operation. The efficiency of these beads was evaluated for removal of cesium from alkaline medium, in batch conditions, using a radioanalytical technique. The effect of sodium ion concentration, the initial cesium ion concentration and the contact time were also investigated. It was observed that the K d value for Cs + ions decreases with increase in Na + ion concentration. The equilibrium data were fitted into different isotherm models, and were found to be represented well by the Langmuir isotherm equation, with a monolayer sorption capacity of 287 mg g 21 . Kinetic modeling analysis, using pseudo first-order, pseudo second-order and intraparticle diffusion equations, shows that the pseudo secondorder equation is the most appropriate model for the description of the sorption of cesium ions onto the RF-XAD beads. The rate constants were determined at different initial concentrations. The process mechanism was found to be complex, consisting of both surface sorption and pore diffusion.

Micro/nanostructured porous Fe–Ni binary oxide and its enhanced arsenic adsorption performances

“…It has been found that the adsorption isotherms for both As(III) and As(V) can be well described by Langmuir model, which is applicable for the monolayer adsorption on the surface containing a finite number of identical active sites, or [59] …”

A Rothmund–Kornfeld model of Cs+–K+–Na+ exchange on spherical resorcinol-formaldehyde (sRF) resin in Hanford nuclear waste

“…This high selectivity is thought to be related to the cation dehydration process at phenol groups on the resin [6]. Other countries around the world are also developing ion-exchange processes around resorcinol formaldehyde resins [7][8][9][10][11]. Resorcinol-formaldehyde resins are more selective for cesium than for potassium, but are more selective for potassium than for sodium.…”

Removing rubidium using potassium cobalt hexacyanoferrate in the membrane adsorption hybrid system

“…Resorcinol formaldehyde (RF) resin was employed in this study for the recovery and purification of Rb that was desorbed from KCoFC after the adsorption experiment with synthetic seawater solution. RF resin is a useful phenolic resin which is formed by the polycondensation of resorcinol and formaldehyde in alkaline solution and used to remove Cs from radioactive solutions [31,32]. RF resin was prepared by mixing resorcinol, formaldehyde, NaOH and H 2 O at a molar ratio of 1:2.5:1.5:50 according to the procedure utilised by Samanta et al [31].…”