Optimum Configuration of 2-stage Hybrid Constructed Wetlands for Treating Hydroponic Waste Solution in Hydroponic Greenhouses.

To obtain optimum configuration of 2-stage hybrid constructed wetlands (CWs) for treating of hydroponic waste solution (HWS) which was produced in greenhouse area, the study consisted of 4 combined systems such as Vertical flow (VF) – Horizontal flow (HF), VF-VF, HF-VF and HF-HF CWs. In four configurations of CWs, the treatment efficiency of pollutants from HWS under depth of HF and VF beds, HWS loading and HWSs was investigated. 2-stage hybrid CWs was in the order of 50 cm < 70 cm regardless of CWs configuration. Removal rate of pollutants under HWS loading in 2-stage hybrid CWs was in the order of 150 L m^-2 day^-1 °Ö 300 L m^-2 day^-1 £¾ 450 L m^-2 day^-1. Removal rate of pollutants in four configurations of CWs showed the similar results for various HWSs (cucumber, paprika and strawberry HWS), in 2-stage hybrid CWs. The optimum depth and HWS loading were 70 cm and 300 L m^-2 day^-1 in four configurations of CWs, respectively. Under the optimum depth and HWS loading conditions in all configurations of CWs, removal rate of BOD, SS, T-N and T-P was 86, 81, 42 and 87% for VF-HF CWs, 89, 84, 32 and 90 % for VF-VF CWs, 87, 83, 43 and 93% for HF-VF CWs, and 84, 84, 51 and 93% for HF-HF CWs, respectively. Optimum configuration of 2-stage hybrid CWs for treating hydroponic waste solution in hydroponic greenhouses was HF-HF CWs.