Selective strontium adsorption using synthesized sodium titanate in aqueous solution.

Amorphous sodium titanates were synthesized using a mid-temperature sol-gel method for evaluation as selective adsorbents of strontium in the presence of cesium or metal cations (Al, Mg, Ca, and Mn) from aqueous solution. Synthesized sodium titanate showed high adsorption capacity and selectivity for strontium. The maximum adsorption capacity of strontium by sodium titanate was 193.93 mg g in aqueous solution containing an initial concentration of 5 mM (438.60 mg L) strontium and 5 mM (666.67 mg L) cesium, and this sodium titanate removed 99.9% of the strontium and 40.67% of cesium from an aqueous solution that had an initial concentration of 1.14 mM (100 mg L) strontium and 0.75 mM (100 mg L) cesium. Strontium adsorption by synthesized sodium titanate followed pseudo-second-order kinetics and a generalized Langmuir isotherm model, and reached an adsorption equilibrium within 1 h with high adsorption capacity at equilibrium. Adsorbed strontium onto synthesized sodium titanate showed the behavior of forming a strontium titanate structure with a titanate frame surface precipitation.