Determination of design criteria to enhance nutrient removal by vertical flow-through wetlands

This thesis has satisfactorily examined the performance of laboratory scale vertical flow constructed wetlands on removing nitrogen under unsaturated and saturated conditions. Manipulating the substrate conditions by adding two different external carbon sources (sucrose and ethanol) was then examined to enhance the removal process. The impact of these manipulations on internal clogging was also investigated. This clearly concludes that operating a fully saturated zone is an effective and economical option in the absence of activated sludge, but the effect was weakened with activated sludge addition. Plate clogging at the inlet area had a major impact on declining outflow rates over time to a greater extent than internal pore clogging.