MECHANICAL AERATION IN POND AQUACULTURE

摘要

Mechanical aeration for supplementing dissolved oxygen in waters has become a standard practice in aquaculture. Standard aeration equipment for wastewater has been modified to provide less expensive equipment for aquaculture. The most commonly used aerators for large ponds are paddle wheel aerators and propeller-aspirator-pump aerators. Diffused-air aeration systems and vertical-pump aerators are widely used in small ponds, hatcheries, and holding tanks. Most aquaculture aerators have standard aeration efficiencies above 1 kg O_2/hp.hr and many have values above 1.5 kg O_2/hp·hr. Aerators usually cost $300 to $500 per horsepower, and in ponds, aeration is applied at rates from 1 or 2 hp/ha to more than 10 hp/ha. Each horsepower of aeration will allow production to be increased by 400 to 500 kg. The cost of aeration varies from $0.05 to $0.10 per kilogram for fish in the United States to as much as $0.40 to $0.50 per kilogram for intensive culture of marine shrimp in Asia. Mechanical devices for circulating pond water may sometimes be used to supplement aeration. Greater efficiency of aeration would result if aerator operation could be automatically adjusted to dissolved oxygen concentrations in ponds.