Uptake ability of heavy metal ions by amorphous CaAl₂Si₂O₈ in mixed ion systems

Abstract

We have reported that amorphous CaAl₂Si₂O₈ prepared by mechanochemical mixing for 24 h and firing of kaolinite and CaCO₃ at 800°C shows good uptake ability and high selectivity for heavy metal ions. In this report, the uptake ability of the amorphous CaAl₂Si₂O₈ was investigated using mixed ion solutions, i.e. four ion mixing (Ni²⁺, Co²⁺, Zn²⁺ and Cu²⁺), three ion mixing (Ni²⁺, Co²⁺ and Zn²⁺) and two ion mixing (Ni²⁺ and Co²⁺). As a result, uptake becomes higher as Co²⁺ < Ni²⁺ < Zn²⁺ < Cu²⁺ in order. This relation is thought to be relating with their ion products.