Composition and method to reduce sediment and bacterial contamination from water
In recent years, a great deal of attention has been drawn to the issue of water contamination, particularly in developing countries, where an inexpensive, effective method of reducing waterborne pathogens and contaminants is needed. Experiments performed with mucilage extracted from the Opuntia ficus - indica cactus show that this mucilage is an effective tool for clearing contaminants from water supplies, including the removal of Escherichia coli and Bacillus cereus bacteria, and the reduction of arsenic concentrations with very low mucilage concentrations (5 mg/L and 10 mg/L). Results for Bacillus and E. coli show settling to be complete in approximately five to ten minutes with removal rates of up to 97%, when CaCl 2 is co-applied. Arsenic is removed at between 35% to 85% by increasing the contact time between the mucilage and the arsenic solutions depending on the pH and mucilage concentration.
1. A method of removing a bacterial contaminant from water, comprising the steps of:
providing a sample of water containing a bacterial contaminant wherein the bacterial contaminant is Escherichia coli;
adding a predetermined amount of salt to the water, wherein the salt is calcium chloride wherein the calcium chloride is added at a final concentration of 20 mM;
adding an isolate of cactus mucilage to the water, wherein the cactus mucilage is a non-gelling extract isolated from a cactus;
wherein the non-gelling extract is isolated comprising the steps of:
liquefying cactus plant pads to form a suspension;
neutralizing the pH of the suspension;
centrifuging the suspension to separate solids from a liquid supernatant;
collecting the liquid supernatant;
mixing the liquid supernatant with a sodium chloride solution to form a pulp;
adding acetone to the pulp at a ratio of acetone to pulp of 1:2 to form a precipitate;
washing the precipitate with isopropanol at a ratio of 1:1;
wherein the nongelling extract is added at 1 ppm to 5 ppm;
allowing the bacterial contaminant in the water to settle; and
removing between 55% to 70% of the bacterial contaminant from the water.
2. The method of claim 1 , wherein the plant is Opuntia ficus indica.
3. The method of claim 1 , wherein the nongelling extract is added to the water at 3 ppm.
4. The method of claim 1 , further comprising removing the water from the upper surface of the water sample, thereby removing the contaminant from the water.