Waste and particle management in a commercial, partially recirculating trout farm

摘要: Abstract The present case study, deals with a recently built aquaculture facility using 80–120 L s −1 spring water for trout production. farm consists of six raceways, discharging in common outflow channel, leading to drum filter equipped 80 μm gauze. About 120 L s the microscreen effluent is pumped back inflow channel raceways. remaining oxygenated pure oxygen gravity oxygenation units and led two U-shaped finally filtered by 63 μm mesh size. backwash sludge treated cone settler, where sediments are extracted agricultural manure application. sedimentation supernatant further sub surface flow (SSF) constructed wetland prior discharge. Due advanced treatment within farm, total effect on receiving kept minimum. nutrient increase produced only 0.03 mg L phosphorous (TP), 1.09 mg L biological demand (BOD 5 ) and, 0.57 mg L suspended solids (TSS) brook. Especially incorporation an intermediate recirculation, prevents leaching dissolved nutrients from particulate matter, as large particles effectively fast possible removed flow. At pumping station, needed particle size distribution (PSD) was monitored previous use by-passed. When screen by-passed significant crushing PSD through action found. Through removal particles, station prevented, revealed measurement. Thus, prevented twice. In consequence, configuration can be recommended effective possibility intensive production at sites small freshwater source stringent thresholds, even unexpected low efficiencies measured microscreens. Both filters showed relative 33–53% solids, respectively, while efficiency 70% should expected PSD. With this impact, still emitted amount, especially due highly offline treatment, SSF efficiently reduced nitrite (NO 2 -N), nitrate 3 -N) TSS. Thus application might suitable denitrification step closed recirculating farm.