Preparation and Physicochemical Evaluation of Biodegradable Magnetic Κ-Carrageenan Beads and Application for Chromium Ions Pre-Concentration

Abstract

This study aims to examine the ability of magnetic Қ-carrageenan beads as an adsorbent in solid phase extraction towards chromium ions from aqueous solution. In this study, Қ-carrageenan magnetic gel-beads were obtained via interphase technique. The beads were kept in 0.3 M KCl to maintain gel strength. Physicochemical of the resulting materials were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and magnetometer. FTIR results have confirmed the presence of functional groups such as sulphate esters groups. The diameter of carrageenan beads was about ~764 μm where SEM micrographs showed the spherical formed shape of carrageenan beads and a rough surface with pores. The saturation magnetization value, M c , of carrageenan beads in this study was 18.78 EMU/g. The magnetic function of carrageenan beads is to facilitate bead collection and to get the Cr 6+ ion that adsorbed onto the beads. The adsorption of chromium ions by magnetic carrageenan beads are through an ion exchange mechanism and formation of metal-ligand complex. Optimal timing for adsorption of chromium ions was at 60th minute. The optimal operation conditions can be achieved on pH value~1 and concentration of 100 ppm. Langmuir adsorption isotherm curve for Cr 6+ is similar to Langmuir adsorption isotherm types III (unfavorable).

Preparation of a superparamagnetic nanocomposite hydrogel for adsorptive performance in the wastewater treatment

“…The hydrogels were prepared according to the method described by Nazarudin et al . The mixture containing the carrageenan solutions (kappa and iota) and magnetic material was added dropwise at room temperature with a metering pump (peristaltic pump) into a beaker containing the crosslinker solution (KCl or CaCl 2 ), at two concentrations (0.3 and 0.5 mol.L −1 ).…”

“…The Q values of the different hydrogels were calculated with eq. …”

“…Hydrogels composed of polysaccharides with magnetic properties have been shown promising materials for application in many sectors …”

“…Nazarudin et al . prepared hydrogels based on κ‐carrageenan containing particles of magnetite, by means of an interphase technique, where the carrageenan solution containing the magnetite was added dropwise in a recipient containing oil and the aqueous phase (KCl).…”

Development of functionalized carrageenan, chitosan and alginate as polymeric chelating ligands for water softening

“…They are used for valuable and important applications because they have many features and properties such as being renewable, non-toxic, biocompatible and biodegradable. Furthermore, they are considered as lowcost materials in comparison with some of the synthetic materials (Ali et al 2013;Elnashar 2010, Elnashar and Hassan 2014and Elnashar 2011Deans and Dixon 1992;Nazarudin et al 2011;Seki and Suzuki 1995;Jang et al 1991). Carrageenan, chitosan and alginate are natural and biodegradable biopolymers that are suitable for developing novel types of materials containing different functional groups (sulfate, amino and carboxylic acid, respectively) for different applications (Nah and Hwang 2007;Zhao et al 2011).…”