Papers by Keyword: Composite Beads

Abstract: The main objective of this study was to characterize and investigate the performance of sodium alginate (SA)-based composite beads as adsorbents for manganese removal from the aqueous solution. In this study, 2% (w/v) of sodium alginate solution was prepared. The SA beads, SA-PCC (SA-P) beads, SA-BMnO (SA-B) beads, and SA-PCC-BMnO (SA-PB) beads were formed by mixing with ionic gelation in a crosslink solution of calcium chloride (CaCl₂). The composite beads were characterized using FESEM and thermogravitmetry analysis (TGA). According to FESEM micrographs, all the adsorbents were spherical in shape, with an average diameter of 1.40 mm to 1.50 mm. The results of TGA demonstrated that SA-PB beads had improved thermal stability and exhibited the highest manganese removal efficiency, with a percentage of removal of 96.14%.

Abstract: A new type of poly(vinyl alcohol)(PVA)/peat/clay composite bead was prepared and shown to be suitable for use as an adsorbent. The mass transport process for the adsorption of metal ions onto the composite beads in an aqueous system was investigated. In the external mass transport process, the rate of ion diffusion decreased and increased with increasing initial metal ion concentrations for Pb+2and Zn+2 ions, respectively. In the intraparticle diffusion process, the diffusion coefficient decreased with increasing initial metal ion concentrations in the range of 1×10-3 to 4×10-3 M, and the diffusion coefficient maintained an almost constant value in the range of 6×10-3 to 22×10-3 M. The rate of ion diffusion within the adsorbent for the Pb+2 ions was faster than that for the Zn+2 ions. The adsorption mechanism was controlled by the intraparticle diffusion process. The maximum amount of adsorbed metal ions at adsorption equilibrium for Pb+2 and Zn+2 ions in this study was 134.57 and 13.28 mg/g composite bead, respectively.

Abstract: Alginate/silica composite beads of mm-size for biomedical applications were prepared from water glass and sodium alginate via a simple sol-gel route. They kept their original shapes when soaked in the phosphate solution of lower pH. In this case, faint calcium phosphate peaks were observed in X-ray diffraction. Peaks corresponding to phosphate group were also found in FT-IR. Apatite was obtained on the surface of beads made with calcium chloride after soaking in phosphate solution while monetite was formed on the surface of beads made with calcium nitrate.