Comparative study on Pb2+ removal using hydrothermal synthesized beta-SrHPO4, Sr-3(PO4)(2), and Sr-5(PO4)(3)(OH) powders

摘要

In this work, beta-SrHPO4, Sr-3(PO4)(2), and Sr-5(PO4)(3)(OH) (SrHAp) powders were successfully prepared by a controllable hydrothermal method and were utilized in removal of lead ion (Pb2+). The effects of pH value, contact time and initial ion concentration on the immobilization of Pb2+ were investigated systematically. Results showed that beta-SrHPO4 exhibited a capacity of 1438 +/- 45 mg/g for Pb2+, while Sr-3(PO4)(2) and SrHAp showed values of 1223 +/- 45 mg/g and 543 +/- 45 mg/g respectively under the optimum conditions. The XRD, SEM and EDX results revealed that the mechanism of Pb2+ immobilization by beta-SrHPO4, Sr-3(PO4)(2) and SrHAp was mainly due to a process of dissolution and precipitation in the acidic solution. Comparing the immobilization behavior and capacities of beta-SrHPO4. Sr-3(PO4)(2) and SrHAp for Pb2+ removal, it is shown that beta-SrHPO4 is an effective and eco-friendly material for the removal of Pb2+ from acidic aqueous solutions among strontium phosphates materials. (C) 2017 Elsevier B.V. All rights reserved.