VATIS UPDATE Article

A Lecturer from University of Guyana (UG), Guyana has invented a technology that could use cactus to help deal with oil spills. Dr. Dawn Fox, in the Department of Chemistry, has been listed as an inventor on US Patent 9,163,374. “The patent was issued for an innovative technology: using cactus mucilage as a dispersant and absorbant for oil in oil-water mixtures,” said UG. The invention consists of employing cactus mucilage as the active ingredient. Cactus mucilage is an extract from the tuna cactus (Opuntia ficus-indica) also known as nopal.

The mucilage is a natural hydrogel polysaccharide found in many water storing succulents including aloes and slimy vegetables. It swells in water but remains insoluble and is able to precipitate bacteria, suspended solids and ions from water. UG explained that conventional chemical clean-up of oil spills utilizes dispersants that reduce the surface tension of water allowing oil and water to mix; this is emulsification. This causes the oil layers to break up into smaller droplets allowing more efficient biodegradation.

In laboratory trials, the mucilage showed ability to both disperse/break up oily layers as well as to absorb oil from oil-water mixtures. Both methods of action are critical for targeting oil slick. Dispersal allows gases to dissolve in the water bodies which would reduce fish kills. The mucilage stays afloat while absorbing the oil layer which facilitates the ultimate physical removal of the oil-mucilage complex. This material is environmentally-friendly and readily available which make it an attractive alternative for a competitive technology to clean up oil spills.