No abstract

In this study alginate/perlite composite particles obtained by ionic gelation method were characterized and their usability on the removal of Pb (II) and Ni (II) ions from aqueous solutions was tested. The effects of pH, contact time, initial metal ion level and perlite concentration on the adsorption capacity of particles were investigated in a batch system. Desorption of tested heavy metal ions from particles and reusability of particles were also investigated. Optical microscopy analysis showed that diameters of wet and dried particles were between 2.5-2.8 mm and 1.8-1.9 mm, respectively. Incorporation of perlite decreased the swelling degree of the particles. SEM and SEM-EDX analysis indicated that perlite appeared as thin plates and mainly composed of silica. SEM-EDX also indicated that alginate/perlite particles were composed of C, O, Na, Al, Si, and K. XRD analysis indicated that perlite had amorphous structure and distributed in the alginate matrix. According to TGA analysis, perlite improved the thermal properties of particles. The optimum pH value varied between 6 and 7 for the removal of Pb (II) and Ni (II). The adsorption efficiency of particles reached maximum level while the perlite/alginate (wt. /wt.) ratio was 2.

spherical with rough surface. SEM-EDX showed that alginate/perlite microspheres composed of C, O, Na, Al, Si, K, Cl and Fe. TGA analysis indicated that incorporation of perlite improved the thermal properties of microspheres. Adsorption capacity of microspheres reached the maximum value when the perlite/alginate ratio=2 (wt./wt.), but then adding more than this value significantly decreased the adsorption capacity of microspheres.