Plant growth and pollutant removal from wastewater in domiciliary constructed wetland microcosms with monoculture and polyculture of tropical ornamental plants

This study investigated pollutants (fluoride, chloride, nitrate, ammonia, phosphates, sulphate and total and volatile solids) removal efficiency from domestic wastewater and plant growth during 195 days in domiciliary constructed wetland (DCWs) microcosms. DCWs were planted with monoculture of Canna hybrid, Alpinia purpurata and Hedychium coronarium and polyculture of the same ornamental flowering plants (OFP), having river rock as a porous substrate. All OFP survived in the DCWs conditions without physical damage. C. hybrid showed the highest length and volume of roots and the highest height and number of flowers than other species in both, mono and polyculture systems. H. coronarium, did not produce flowers. A. purpurata grew better in monoculture than polyculture. Ammonia nitrogen removal was significantly higher in DCW microcosms with monocultures of C. hybrid than with monocultures of A. purpurata (p=.037), but no significantly different than monocultures of H. coronarium (p=.466), Contrary, removal efficiency of this ion was significantly higher in polyculture than mocultures of A. purpurata (p=.024) and H. coronarium (p=.0.032) but no significantly different than monoculture of C. hybrid.The other parameters were removed similarly in both cultures of plants (20-81%; p >.05). Polycultures of OFP are a good option for wastewater treatment in DCWs.