Evaluating Wastewater Treatment Efficiency of Two Field Scale Subsurface Flow Constructed Wetlands uri icon

abstract

  • designed to treat a variety of industrial, domestic andagricultural waste waters. We study here the efficiencyof domestic waste water treatment by two field scalesubsurface flow CWs under different hydraulic loadingrates (HLRs). Each CW had inlet and outletchamber for waste water collection with Pistia stratiotes(water lettuce), two treatment sections consisting ofsand and gravel media and four plant species Typhalatifolia (Broadleaf cattail) and Cymbopogon citratus(lemon grass ? first CW) and (Pennisetum purpureumschum and Pennisetum americanum L (Hybrid napier)and Urochloa mutica (Paragrass ? second CW). Thewastewater source was from a residential urban colony.The HLRs for the first and second CW for athree-month period averaged 4.45 cm/day and5.77 cm/day respectively. The CW was monitored forquality of wastewater inflows and outflows and nutrientaccumulation in plants and sand media. Resultsshowed that the chemical oxygen demand (COD), totalsuspended solids (TSS), total nitrogen and total phosphateremovals in the first and second CW over athree-month period averaged 42%, 74%, 39% and41% and 34%, 82%, 14% and 35% respectively. Boththe CWs showed similar rates of TSS removal irrespectiveof the type of wetland plant species. Over thethree-month period, average COD, total nitrogen andthe phosphate removals were greater in the first CWcompared to the second CW. These results confirmthe efficacy of field scale subsurface flow CWs toimprove the quality of domestic waste water in ruralcommunities of developing countries like India

publication date

  • 2016
  • 2016