Effect of the magnetic core in alginate/gum composite on adsorption of divalent copper, cadmium, and lead ions in the aqueous system.

The change of composition of an adsorbent material has been widely used as a method to increase its adsorption capacity, particularly concerning adsorbents made of polysaccharides. Introducing magnetic adsorbents into contaminated water treatment systems is a highly promising strategy, as it promotes the metal ions removal from water. Considering this, gum Arabic (GA) was associated with alginate (Alg), when magnetite nanoparticles were present or absent, to produce beads that were utilised to take up Cu(II), Cd(II), and Pb(II) from aqueous solution. After a complete characterisation (for which Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and swelling were used), the adsorption properties were established using batch and column tests. The magnetic beads (MAlg/GA) demonstrated improved adsorption in comparison with the beads made without magnetite (Alg/GA) under the same conditions. In normal adsorption conditions (pH 6.0, 25 °C, 2.5 g L-1 of adsorbent dosage), the highest uptake capacities recorded for the MAlg/GA beads were: for Cu(II), 1.33 mmol g-1; Cd(II), 1.59 mmol g-1; and for Pb(II), 1.43 mmol g-1. The pseudo-second-order kinetics and Langmuir isotherm models provided good fits for the adsorption of these metals. Overall, ion exchange and physical forces led to the uptake of these metals by both Alg/GA and MAlg/GA; moreover, the functional groups on the beads played crucial roles as binding sites. Additionally, it was observed that flow rates of >2 mL min-1 did not produce noticeable changes in uptake levels over the same flow period. It was found that the efficient eluting agent was HNO3 (0.2 M). In some cases, the metals were not removed fully from the used beads during the first five cycles of regeneration and reuse. The results of this investigation show that these beads are efficient adsorbents for the removal of metal ions from spiked well water samples.

Synthesis of Gum Arabic-g-polyaniline using diode laser.

Grafting of polyaniline (PANI) on Gum Arabic (GA) was carried out in the presence of ceric ammonium nitrate (CAN) under acidic conditions by diode laser as initiator. The grafting condition was optimized by varying the diode laser power, exposure time, concentrations of PANI, CAN, GA, reaction time and temperature were carefully optimized to achieve the highest percentage of grafting yield % GY (90%) and percentage of graft efficiency % GE (36%). The Fourier-transform infrared spectroscopy (FTIR), 1H NMR, X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), and Scanning electron micrographs (SEM) techniques have been used for the characterization of the produced graft copolymer GA-g-PANI, which used as drug delivery carrier to control cancer in brain. This study focused to new trends and latest developments in this area where diode laser was found to be efficient and, clean method for synthesis GA-g-PANI.