Constructed wetlands for water quality regulation

Abstract

Constructed wetlands (CWs) have been used for wastewater treatment since the 1960s. Constructed wetlands are engineered systems that have been designed and constructed to utilize natural processes involving wetland soils, vegetation, and microbes to treat wastewater. Constructed wetlands may be categorized according to the various design parameters, but three most important criteria are hydrology (surface flow and subsurface flow), type of macrophytic growth (emergent, submerged, free-floating), and flow path (horizontal and vertical). Different types of constructed wetlands may be combined with each other, i.e., hybrid or combined systems, to utilize the specific advantages of the various systems. CWs are used to treat municipal sewage, as well as agricultural and mine drainage, industrial effluents, landfill leachate or stormwater runoff. Constructed wetlands are considered as reliable and robust treatment systems with low maintenance and operation costs.