Novel biopolymer-coated hydroxyapatite foams for removing heavy-metals from polluted water

Abstract

3D-macroporous biopolymer-coated hydroxyapatite (HA) foams have been developed as potential devices for the treatment of lead, cadmium and copper contamination of consumable waters. These foams have exhibited a fast and effective ion metal immobilization into the HA structure after an in vitro treatment mimicking a serious water contamination case. To improve HA foam stability at contami-nated aqueous solutions pH, as well as its handling and shape integrity the 3D-macroporous foams have been coated with biopolymers polycaprolactone (PCL) and gelatine cross-linked with glutaraldehyde (G/Glu). Metal ion immobilization tests have shown higher and fast heavy metals captured as function of hydrophilicity rate of biopolymer used. After an in vitro treatment, foam morphology integrity is guar-anteed and the uptake of heavy metal ions rises up to 405 mol/g in the case of Pb2+, 378 umol/g of Cu2+ and 316 umol/g of Cd2+. These novel materials promise a feasible advance in development of new, easy to handle and low cost water purifying methods.