PURPOSE: To improve fixation ratio of carbonate ion or bicarbonate ion by bringing a solution or a solid material containing carbonate ion or bicarbonate ion into contact with an Al-Mg compound oxide shown by a specific formula.
CONSTITUTION: An Al-Mg compound oxide shown by the formula (X is ≤1 positive number 0<n<1.5) is molded into a granular state by using a binder or powder is supported on a carrier. Then, a solution or a solid material containing carbonate ion or bicarbonate ion and another inorganic anion such as sulfate ion, nitrate ion, phosphate ion, silicate ion or chloride ion is contacted with ≥0.5g, based on 1mol existing carbonate ion or bicarbonate ion, of Al-Mg compound oxide for several minutes to several hours. Then the Al-Mg compound oxide having fixed carbonate ion or bicarbonate ion is separated and removed to give a solution or a solid material having extremely reduced carbonate ion or bicarbonate ion.
AIBA NOBUHIKO
INOE HIDETAKE
