Compartment | Function | Targeted parameters | Expected reactions |
---|---|---|---|
Fish tank (aerobic loop) | Fish holding | Dissolved oxygen close to or at saturation, low total nitrogen, total organic carbon, NH4+ and NO2− | Nitrification, aerobic respiration |
Drum filter (aerobic loop) | Removal of the solids via mechanical filtration | Low suspended solids after the filtration | None |
Biofilter (aerobic loop) | Oxidation of total ammonia nitrogen and nitrite to nitrate | Dissolved oxygen close to or at saturation, low NH4+ and NO2− | Nitrification, aerobic respiration |
UV treatment (aerobic loop) | Water disinfection | None | None |
Oxygenation zone (aerobic loop) | Saturation of the system water with oxygen | Dissolved oxygen at saturation | None |
Sump (aerobic loop) | The connection between aquaculture and hydroponic part of the system, serving as a hydraulic buffer | High oxygen saturation, high NO3− and low NH4+ and NO2− | Nitrification |
Hydroponic table (aerobic loop) | Plant holding on a thin layer of water with floating polystyrene foam rafts | High oxygen concentration, high NO3−, low NH4+ and NO2− | Nitrification, plant nutrient uptake, carbon input by rhizodeposits, microbial respiration |
Radial flow settler (aerobic and naerobic loop) | Passive filtration by using gravity to remove settable solids | Inflow: High concentration of suspended solids, total organic carbon and total nitrogen, higher NH4 compared to the outflow Outflow: Reduced suspended solids and TN compared to the inflow | Nitrification, denitrification, ANAMMOX, microbial fermentation, mineralization |
Anaerobic digester (anaerobic loop) | Anaerobic sludge digestion to obtain supernatant rich with nutrients and recycle the water | High nutrient concentration, no/low oxygen, low redox potential, high solids, accumulation of NH4 | Denitrification, acidogenesis, hydrolysis, iron and sulfate reduction, sulfate oxidation, carbon mineralization, methanogenesis, dissimilatory nitrate reduction |