| Popis: |
In the last decade an extraordinary amount of research and development has focused on alleviating problems associated with contaminated water. With the majority of the World's population living on the brink of illness due to bacterial contamination in town water supplies, much of this attention has been focused on bacteria removal and sensors. Many current decontamination techniques are too technologically advanced for less developed countries, often resulting in their rejection by the societies they serve. Sensor work has also come across problems including poor sensitivity making it difficult to detect microorganisms at low concentrations. We have been testing a material extracted from the Opuntia ficus-indica cactus which could possibly address both of these problems in conjunction with one another. This material, referred to as cactus mucilage, has proven itself in the past as a viable flocculating agent for use in water contaminated with sediments and heavy metals. Flocculation tests, now focused on Bacillus cereus and Escherichia coli, have also given insight on the mucilage's ability to gather and concentrate bacterial contaminants from ion-rich water supplies. In columns with bacteria suspended in hard and soft water, flocculation begins immediately and is complete in approximately five to ten minutes with concentration rates of up to 99%. In addition to cleaning the water, the flocs formed with the mucilage could be removed from the water for sensor use. Cactus mucilage is an ideal material for water treatment and assessment because it is a naturally occurring, low cost material that is easy to obtain, process and use. Using this type of green chemistry, not only are bacteria concentrations significantly lowered in contaminated water, but also a highly concentrated volume of bacteria is produced that could potentially aid in biosensors. |
