Cooling and Reuse of Thermal Discharges

Thermal pollution is produced by industries such as electric power plants, pulp and paper mills, chemical facilities, and other process industries that use water and subsequently discharge water with elevated temperature. The receiving streams, rivers, lakes, and other waters can dramatically alter the native environment. Often, elevated water temperature will be detrimental to native species of plants and animals. As water warms, the solubility of oxygen decreases. In addition to promoting competitive species of plants and animals, warmed waters may lead to aesthetic and odor problems if anaerobic conditions are created. For these and many other reasons, the discharge of warm process water is widely regulated by governmental agencies in developed nations. The authors introduce both cooling ponds and cooling towers in detailed. The cooling pond topics covered are mechanism of heat dissipation, cooling pond types and design, completely mixed cooling, recirculation cooling, surface temperature prediction, longitudinal mixing, heat dissipation evaluation, once-through cooling ponds, seasonal weather variation, pond location, cooling, etc. The cooling tower topics covered are mechanism of cooling tower’s heat dissipation, cooling tower types and designs, natural draft atmospheric cooling towers, natural-draft wet hyperbolic cooling towers, design examples, hybrid draft cooling towers, induced, mechanical or forced wet cooling towers, cooling tower performance, operational problems and solutions, and reuse of thermal discharge.