Constructed Wetlands and Water Hyacinth Macrophyte as a Tool for Wastewater Treatment: A Review

This paper is an attempt to study the water treatment processes with special emphasis on construction wetlands (CW's). Wastewater is a growing concern in different developed countries. Hence treatment of wastewater has gained much importance. There are different levels of water treatment of which constructed wetlands come under secondary level. The types of constructed wetlands include free water surface CW's, CW's with horizontal subsurface flow, CW's with vertical subsurface flow and hybrid CW's. A comparison is done for both the surface flow types. Macrophytes form an important part of constructed wetlands and in this paper the effectiveness of a bio-hedge based water hyacinth system is emphasized. An outline of the sand filtration technique is also provided. The different factors that are to be removed from the waste water and the mechanisms used for their removal are also concentrated