UVI aquaponics system designe

James Rakocy, Donald Bailey

Charlie Shultz and Jason Danaher

University of the Virgin Islands

Agricultural Experiment Station

St. Croix, U.S. Virgin Islands

System Design

Four fish rearing tanks, 7.8 m3 each

Two cylindro-conical clarifiers, 3.8 m3 each

Four filter tanks, 0.7 m3 each

One degassing tank, 0.7 m3

Six hydroponic tanks, 11.3 m3 each

Total plant growing area, 214 m2

One sump, 0.6 m3

Base addition tank, 0.2 m3

Total water volume, 110 m3

Land area - 0.05 ha

Treatment Processes

Air stones, 22 per rearing tank, 24 per hydroponic tank

Solids removal, three times daily from clarifier,filter tank cleaning one or two times weekly

Denitrification in filter tanks

Continuous degassing of methane, CO2, H2S, N2

Direct uptake of ammonia and other nutrient by plants

Nitrification in hydroponic tank

Retention time: rearing tank, 1.37 h; clarifier, 20 min,hydroponic tanks, 3 h

filter electric locomotive pipeline filter vertical flow settler buct grid filter clean grid clean grid Cesspool running filter hydroponic grow bed vegetable

Treatment Characteristics

Removal rates using romaine lettuce (g/m2/d):

NH3

-N, 0.56

NO2

-N, 0.62

COD, 30.3

Total nitrogen, 0.83

Total phosphorous, 0.17