Sugarcane as constructed wetland vegetation: preliminary studies

Abstract

This study investigated the potential of sugarcane as vegetation in constructed wetlands (CW). The possibility of using sugarcane in CW has not been reported to date, but may represent a way to increase the sustainability of these wastewater treatment systems, since its biomass can be used for bioethanol production. The preliminary studies herein described were conducted in order to evaluate the behaviour of sugarcane in laboratory scale CW. At the same time, different mineral materials were tested as support media for plant growth, because the use of alternative low cost filling materials represents in itself another way to make CW more sustainable. The lab-scale CW consisted of four pots with the different mineral fillers tested (expanded clay, limestone, basalt and clay brick fragments) and one plant each (Saccharum officinarum), subjected to an average hydraulic loading rate of 419±24L/m-2day-1 of low strength wastewater. The study lasted 23 weeks, during which a regular growth of the plants was observed as well as a reasonable performance of the lab-scale CW in terms of nutrients removal from wastewater, particularly phosphorus compounds. The results obtained are promising enough to motivate a more detailed study of the use of sugarcane as CW vegetation.