Hydrogen peroxide modified sodium titanates with improved sorption capabilities
View Patent ↗The sorption capabilities (e.g., kinetics, selectivity, capacity) of the baseline monosodium titanate (MST) sorbent material currently being used to sequester Sr-90 and alpha-emitting radioisotopes at the Savannah River Site are significantly improved when treated with hydrogen peroxide; either during the original synthesis of MST, or, as a post-treatment step after the MST has been synthesized. It is expected that these peroxide-modified MST sorbent materials will have significantly improved sorption capabilities for non-radioactive cations found in industrial processes and waste streams.
1. A method of synthesizing a peroxide-modified monosodium titanate (MST) sorbent material, comprising:
a) dissolving a titanium alkoxide and a sodium alkoxide in a solvent to make a solvent mixture;
b) adding water and hydrogen peroxide to the solvent mixture, and stirring until yellow precipitates form; and
c) recovering the yellow precipitates, which comprise peroxide-modified MST solids, from the solvent mixture.
2. The method of claim 1 , further comprising:
d) washing the recovered yellow precipitates 2-3 times with deionized water to remove any unreacted hydrogen peroxide; and
e) drying the washed yellow precipitates in air at room temperature; and
wherein the recovering step comprises recovering by vacuum filtration.
3. The method of claim 1 , wherein the ingredients are combined in the following proportions:
5-10 wt % titanium alkoxide;
0.5-1.5 wt % sodium alkoxide;
5-10 wt % hydrogen peroxide;
5-10 wt % water; and
balance solvent;
wherein the Ti:Na ratio of the yellow precipitates is about 2:1.
4. The method of claim 1 , wherein:
the titanium alkoxide is selected from the group consisting of titanium methoxide, titanium ethoxide, titanium propoxide, and titanium butoxide;
the sodium alkoxide is selected from the group consisting of sodium methoxide, sodium ethoxide, sodium propoxide, and sodium butoxide; and
the solvent comprises an alcohol that is miscible in water selected from the group consisting of methanol, ethanol, propanol, butanol, and isopropanol.
5. The method of claim 1 , wherein the titanium alkoxide consists essentially of titanium isopropoxide; the sodium alkoxide consists essentially of sodium methoxide; and the solvent consists essentially of isopropanol.
6. The method of claim 5 , wherein the ingredients are combined in the following proportions:
8 wt % titanium isopropoxide;
1 wt % sodium methoxide;
8 wt % hydrogen peroxide;
8 wt % water; and
balance isopropanol.