Performance of various media in vertical flow constructed wetland for the treatment of domestic wastewater

Studies were conducted on six pilot-scale vertical flow constructed wetland (VFCW) systems for the treatment of real domestic wastewater. All the six VFCWs had identical configurations and was filled with sand at the top and gravel at the bottom. The middle layer of each wetland system was filled with organic media (wood mulch, sugarcane bagasse and coir) and inorganic media (gravel, brick rubbles and pebbles), respectively. All the VFCWs were planted with wetland plant Typha latifolia. During the experimental study, the wetlands were loaded with real domestic wastewater. Performances of the wetlands were evaluated for the removal of organics, nutrients and bacterial contamination. The organic media wetlands had a removal efficiency of biochemical oxygen demand (BOD5) (75%–88%), chemical oxygen demand (COD) (72%–82%), ammonia nitrogen (NH4-N) (63%–70%), nitrate nitrogen (NO3-N) (77%–80%), total nitrogen (TN) (67%–68%) and total phosphorous (TP) (66%–80%). The control and inorganic media wetlands had a removal efficiency of BOD5 (91%–94%), COD (82%–85%), NH4-N (51%–77%), NO3-N (59%–63%), TN (42%–56%) and TP (58%–68%). Total suspended solids and fecal coliform removal was above 88% and 95%, respectively, in all the wetlands irrespective of the media.