Landfill leachate treatment using constructed wetland under different hydraulic loading rate (HLR)

Abstract

Landfill leachate is one of wastewater which is toxic and represent a dangerous source of pollution for the environmental especially water body and groundwater. Constructed wetland is one of natural treatment that can be a reliable and cost effective for landfill leachate which was carried out to identify the potential of constructed wetland in term of its ability in removal of solids, organic matters and nutrients under different hydraulic loading rate of leachate. A laboratory-scale study was conducted on combination of subsurface flow and free water surface system (SSF-FWS), whereas set up to planted and control reactors. Planted reactors were planted with Limnocharis flava in SSF reactor while Eichhornia crassipes as floating plant in FWS reactor. Control reactors were left unplanted. This study was operated at hydraulic loading rate of 0.39 m/d and 0.55 m/d and with retention times of 24 hours. The removal efficiency was evaluated based on pH, turbidity, Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Orthophosphates (PO4 3−), Ammoniacal-nitrogen (NH3-N) and Total Suspended Solids (TSS). There was better performance obtained in planted reactor at HLR of 0.39 m/d. pH value was decrease for 0.39 m/d and 0.55 m/d which are from 8.43-7.185 and 8.43-7.49, respectively. For 0.39 m/d, the removal efficiency of turbidity, BOD5, COD, PO4 3−, NH3-N and TSS were 97.43%, 87.5%, 99.52%, 94.63%, 98.59% and 98.32%, respectively. While, for 0.55 m/d, the removal efficiency were 90.83%, 93.73%, 96.73%, 65.85%, 95.99% and 98.32%, respectively.