NUTRIENT REDUCTION IN AN IN-SERIES CONSTRUCTED WETLAND SYSTEM TREATING LANDFILL LEACHATE

The effectiveness of an in-series surface flow constructed wetland designed to treat landfill leachate was determined by conducting pollutant removal efficiency studies over a 4 month period. The first step in the study involved the characterization of the leachate generated within the landfill. At the same time, ten in-series parallel wetlands with a 10:1 length to aspect ratio were constructed, with each cell designed for a maximum water depth of 0.5m. Cells were planted with a variety of vascular aquatic plants including Sagittaria spp., Pontedaria sp., Scirpus spp., Phragmities sp., Typha sp., Juncus spp., and Zizaniopsis sp.. This system is a component of a solid waste facility of a closed-loop design incorporating recycling, composting and constructed wetlands to treat leachate mixed with septage on site. The system is characterized by a varying hydraulic loading rate and retention time.