Slurry for treatment of oxyanion contamination in water

A method of remediation of contaminated water having oxyanion contamination comprising the steps of:

• selecting an expandable bentonite containing at least 0.5% sodium as disodium monoxide as determined by X-ray fluorescence;
• treating the expandable bentonite with a sodium salt to produce a sodium activated bentonite having more than 3% sodium as disodium monoxide as determined by X-ray fluorescence;
• combining the sodium activated bentonite with water to produce a sodium activated slurry;
• exchanging at least some of the sodium of the sodium activated bentonite with a rare earth salt selected from the group consisting of lanthanum, cerium and dysprosium salt to produce a rare earth exchanged slurry consisting of a rare earth exchanged bentonite and water, the rare earth exchanged bentonite having incorporated therein a rare earth salt, whereby said slurry has a plurality of active sequestration sites, said plurality of active sequestration sites for sequestration of oxyanions;
• and
• distributing the rare earth exchanged slurry in the contaminated water.