US Patent 7381686 - Metal nanoparticle composite for inhibiting algae growth

http://www.freepatentsonline.com/7381686.html

This patent is directed to composites for water purification and teaches a nanoparticulate silver composition to inhibit algae growth. Claim 1 reads:

1. A composite for inhibiting algae growth in water comprising a polypore base carrier and a nano-metal mixture coated on the carrier, wherein the mixture comprising a nano-silver particle and a nano-zinc oxide for fixing the particle on the carrier, and tourmaline, wherein said composite is sufficient to inhibit said algae growth, and convert the water from green to colorless in appearance.