Monday, October 17, 2011: 4:55 PM
L100 I (Minneapolis Convention Center)
The production of potable water is usually very expensive, and involves chemical process such as flocculation and chlorination. The conventional flocculation process includes the use of inorganic salts and organic synthetic polymers as flocculants. Cost and environmental side effects of these flocculants are a public concern. Therefore, more than ever, the demand for environmentally friendly technologies and renewal bioproducts to replace synthetic flocculants in water treatment has greatly increased. Earthquakes or anthropogenic event have the potential to cause direct and indirect detrimental effects on the drinking water quality. The purpose of this study is to investigate cactus mucilage-based separation as a viable alternative treatment for water purification in emergency scenarios. The mucilage is an extract from the Opuntia ficus-indica, commonly known as Nopal or Prickly pear cactus. This readily available and inexpensive natural extract has been shown to remove turbidity, bacteria and arsenic from synthetic water in laboratory trials. It is hypothesized that the mucilage will be able to improve the quality of event-impacted potable water sources by lowering the suspended solids, bacteria and heavy metal content of the water. Samples of tap water (distributed from treatment center), well water, surface water and distributed water (bottled water and from tanker trucks) were collected from several places at a recently affected area: Port-au-Prince, Haiti. Turbidity, total suspended solids, fecal coliforms, biochemical oxygen demand, heterotrophic plate count, conductivity, pH, and trace metals were analyzed to establish the water quality and type of contamination. Up to this point, fifty percent of the evaluated samples have positive presence of coliforms. Water treated with cactus mucilage has lower levels of heavy metals. We have also tested the interactions and efficiency to clean water with surrogated bacteria for cholera, which is commonly seen after natural disasters when the anthropogenic conditions are susceptible. Samples from the top of water columns treated with the mucilage reveal that high bacterial removal rates were achieved. The cactus mucilage is a biomaterial with great potential to be used in water purification because of its long shelf life time, low cost and readily availability through sustainable agriculture.