Use of crystalline intergrowth molecular sieves for removing contaminant metal ions from liquid streams

摘要

A process for removing contaminant metal ions from a liquid stream is disclosed. The process involves contacting the liquid stream with a crystalline molecular sieve which has a crystal structure which is an intergrowth of the pharmacosiderite and sitinakite structures. The molecular sieve has an empirical formula of: A((4-4x)(n)(MxTi1-zGey)4(Ge1-pSip)qOrwhere A is a cation such as sodium or potassium and M is a metal such as niobium or tantalum. These molecular sieves are particularly effective in removing cesium and strontium ions from aqueous streams.