Heavy Metals Immobilization by Hydroxyapatite-Alginate Composite in Simulated Gastric Fluid
Micrometric sphere beads of HA-alginate composite were produced to remove Pb2+ and Cd2+ from contaminated gastric fluid. It was shown that the composite was effective in Pb2+ and Cd2+ immobilization from high-contaminated simulated gastric fluid. X-ray diffraction and scanning electron microscope analyses performed on HA-alginate beads after the Pb2+ uptake showed that lead phosphate, (Pb10-x Cax (PO4)6Cl2), was precipitated on beads surface. X-ray diffraction patterns of HA powder after Cd2+ sorption experiments showed no evidence of other phases, however, dispersive energy spectrometer analyses of the HA-alginate confirmed the presence of Cd2+ on the composite surface. Desorption experiments in simulated enteric fluid showed that composite beads containing Pb2+ and Cd2+ remained stables for one hour in simulated gastrointestinal fluid. The results reinforce the hypothesis that HA-alginate composite can be a very efficient system for Pb2+ and Cd2+ uptake from contaminated gastrointestinal fluid preventing systemic contamination by bloody stream uptake.
Guy Daculsi and Pierre Layrolle
E. Mavropoulos et al., "Heavy Metals Immobilization by Hydroxyapatite-Alginate Composite in Simulated Gastric Fluid", Key Engineering Materials, Vols. 361-363, pp. 467-470, 2008