The Phytoremediation Potential of a Singapore Forest Tree for Bioretention Systems

Tree species have large biomass and extensive root systems, giving them great potential for phytoremediation. It is beneficial to plant native species as these species are naturally adapted to the local climate and growth conditions, and they can support local biodiversity as well. Elateriospermum tapos （E. tapos） Blume tree saplings were investigated in pot experiments to understand their phytoremediation potential. The saplings were planted in a soil-based mediumof known composition with pots of unplanted soil as control. Tap water spiked with 10mg/L nitrate and 2mg/L phosphate was used to represent the highest range of nutrient pollutants found in stormwater in Singapore. Chlorophyll fluorescence and SPAD data showed the plants were healthy throughout the experiments. E. tapos tree saplings showed improved nitrate removal compared to barren pots. In addition, the nitrate removal efficiency of the barren potsdecreased over time, whereas the nitrate removal efficiency of vegetated pots increased over time. A