February 15-18, 2009 Washington State Convention Center Seattle ...

4
LIMITATIONS TO NUTRIENT REMOVAL IN A FLOW-THROUGH AQUAPONICS SYSTEM
Karen M. Buzby*, Todd P. West, Xinchao Wei and Kenneth J. Semmens
Department of Civil and Environmental Engineering
West Virginia University
Morgantown, WV 26506 USA
kmbuzby@mail.wvu.edu
Aquaponics, the simultaneous culture of fish and plants, can increase profits due to crop diversification as well as mitigate
environmental impacts through reductions in nutrient release. In recirculating fish production systems, aquaponics can reduce
nitrate concentrations by greater than 90% while phosphate concentrations can be reduced 50 - 99% depending on the system.
Aquaponics used in conjunction with flow-through fish production systems, such as those used for trout production, have much
lower nutrient removal rates averaging 12-15% for nitrate and phosphate.
Greater volumes of effluent are generated in flow through systems. In addition, the effluent had colder water temperatures and
lower nutrient concentrations which may affect plant nutrient uptake. An experiment examined the effects of increased water
temperatures, increased nutrient concentrations, increased contact time between plants, and effluent and supplemental light in
an effort to improve nutrient removal. The fish raised were brook trout while lettuce and watercress were used as the plant
component.
Figure 1. Nitrate removal by watercress and lettuce