Lead and cadmium immobilization by polymeric sponges coated with hydroxyapatite

Abstract

Polymeric sponges coated with hydroxyapatite were used in lead and cadmium uptake experiments in order to mimetizes heavy metal incorporation by bone tissue. The hydroxyapatitecoated sponges (S-HA) were obtained by hydrothermal alkali conversion from monetite. The results showed that S-HA were efficient in immobilizing Pb and Cd. The uptake experiments using hydroxyapatite powder (HA) removed almost 100% of Pb2+ and 59% of Cd2+. When polymeric sponges coated with hydroxyapatite were used, the removal of Cd 2+ and Pb2+ decreased, respectively, to closely 14 % and 74%, after 24 hours sorption. Before and after sorption experiment MEV analysis indicated precipitation of pyromorphite on hydroxyapatite-coated sponges.