文摘
The removal of NH4+ on protonated layered perovskite oxide HCa2Nb3O10·1.5H2O from an aqueous solutionat room temperature using a batch method was investigated. The protons situated between the layers of thematerial are exchangeable with cations in solution. Distribution coefficient values, Kd (cm3/g), of Na+, K+,and NH4+ cations at pH 2.2 from a mixed solution (NaCl, KCl, and NH4Cl) containing 1.0 mmol/dm3 ofeach ion were 1600 for K+, 2200 for Na+, and 10 500 for NH4+. The effect of solution pH on the ion exchangein aqueous solution (NH4Cl + HCl or NH4OH) showed a maximum uptake of 34 mg of NH4/g at around pH6. The results indicate that the material is very effective for removing NH4+ at concentrations of less than 10mg of NH4/dm3.