Can you provide detail of the kind of water contaminants you are addressing?

Contaminants like toxic compounds present in water

I think yes, because the nanoclay can have a great surface area to adsorb several compounds, so, the nanoclay can be used as support to metal particles and you can use them in pollutant destruction reaction like Fenton. See literature about pillared clays and extropalote it to your question.

Definately, nanoclays and their composites could be used for waster treatment as well for removing humic acid from ground water. Nanoclays are found to effective when combined with other sorbents like activated carbon and alum.

Also, nanoclays are used as filers to enhance abrasion resistance of the polymer based water treatment membranes as little amount of nanoclay alter entire polymer properties.

For further details please refer following articles

http://www.sciencedirect.com/science/article/pii/S0376738813006388

http://link.springer.com/article/10.1007%2FBF02704606

Thankyou very much