Lead and cadmium removal from single and binary metal ion solution by novel hydroxyapatite/alginate/gelatin nanocomposites

Imperfect treatment of effluents from the industries contain moderate amounts of metallic cations will carry other issues to human health and environment. When toxic substances enter into water bodies, they get dissolved in water or get deposited on the bed. This results in the deterioration of water thereby affecting the aquatic ecosystems. In the area of environmental remediation, nanosized materials offer potential for efficient removal of pollutants and biological contaminants. In this present work, heavy metal ions (Pb2+ and Cd2+) sorption capacity of HA-alginate/gelatin nanocomposite has been investigated as a function of adsorbent dosage, adsorbate concentrations and contact time. The sorption kinetics exhibited the best fit to the pseudo-second order equation and the equilibrium followed Langmuir isotherm model. The equilibrium removal capacity of HA/Alg composite from Langmuir isotherm model was evaluated to be 550 and 361 mg/g for Pb2+ and Cd2+. The removal capacity of HA/Alg/Gel composite was evaluated to be 616 and 388 mg/g for Pb2+ and Cd2+. In the case of binary metal ion system, removal capacity of the adsorbent for a particular metal ion was hindered by the presence of another ion in the medium. The results of this study will be useful for further development of ceramic/polymer composites for environmental applications.