DESALINATION OF DRINKING WATER IN FLORIDA
Water Supply Problems That Compel Desalination
Generally. Around the world, primarily in heavily populated zones of the temperate climes, available fresh water sources for municipal-scale, public water supplies have become overtaxed. Either there are shortages, net of demand, or water has been reused so many times that the remaining resource is saltier than is healthy for beasts, plants, or people. At the same time, accumulated brine and even abundant sea water remain available, even inexhaustible, if only desalting technologies can be applied feasibly. Even where fresh water is available, moreover, some commercial processes or machinery require waters of very low dissolved solids contents, such as soft-drink or medicine manufacture or industrial boilers or cooling towers. For these uses, available supplies are normally polished or highly treated for salt removal by individual users. The broadest application for salt removal from water on a municipal scale is the process known as softening, removal of calcium and magnesium--chemicals that interfere with detergent or soap sudsing/ cleansing actions.
Desalting applications also have expanded in part because the finest-mesh membranes suited to desalting are also those that remove the tiniest particles in water (such as microbes) that modern regulatory agencies target in ever-smaller sizes and for their ever-more esoterically perceived harm (Pontius 12-14). Ventresque, Turner, and Bablon describe a membrane application for municipal treatment of the pesticide- and industrially-polluted Oise River--a freshwater source near Paris, France (67).
The best known and assuredly the largest-scale desalination projects that desalt sea water are in the Middle East (Abdulrazzak 227-34; Al-Ibrahim 375-88). Nitrate removal from briny water for drinking purposes has been addressed by Kapoor and Viraghavan (371-80). Softening via desaltin...