Performance Evaluation of Three Native Plants for Sewage Wastewater Treatment in Constructed Wetland

Sewage wastewater was tested the purifying capacity by three constructed wetlands planted with Caladium bicolor (HF₁), (Colocasia esculenta) (HF₂), (Dracaena sanderiana) (HF₃) and HF₄ unplanted. HF_s were loaded with two hydraulic load rates (HLR) at 0.05 m/d and 0.1 m/d. The planted tanks obtained bigger mean removal of total suspended solid (TSS), biochemical oxygen demand (BOD₅) but not clearly with nutrients and total coliform (Tcol). HF planted with Caladium bicolor reached the higher than other HF_s in terms of mean removal efficiency, stable and growth of shoots and roots. The mean removal for HF planted ranged 42 – 50% of BOD₅, 50 – 53% of TSS, 22 – 31% of ammonia (NH₄-N), 49 – 52% of nitrate (NO₃-N), 2 – 8% of phosphate (PO₄-P) and 75 – 81% of Tcol. The effluent concentrations met Vietnam’s standard apart from some samples at 0.1 m/d passed the discharge limit for BOD₅ and Tcol concentrations.

Keywords: constructed wetland, native plant, sewage wastewater