Multi-morphology Hydroxyapatite Microcrystals: Hydrothermal-controlled Synthesis and Their Absorption Upon Pb~(2+)

Multi-hydroxyapatite were synthesized under hydrothermal conditions by adjusting synthesis parameters including the mole ratio of CaCl2 and NaH2PO4(starting materials),temperature,reaction time,pH value,and shape-control agents.A series of investigations were made on the growth conditions of the microcrystals and their absorption upon Pb2+.The results indicate that in the presence of starch,hydroxyapatite microcrystals with varied morphologies were made and the products had strong absorption for Pb2+.Under some conditions,the obtained product could remove as high as 85.42% Pb2+in water,which should be of important application in the treatment of waste water involving Pb2+.