PHYTOREMEDIATION OF NUTRIENT POLLUTANTS BY NATIVE PLANTS

Abstract

Water is a valuable and limited resource in an urban city such as Singapore. One source of water which Singapore can tap into is natural precipitation. During a rain event, rain water flows along impervious surfaces, collecting pollutants in the storm water runoff, before depositing them into drainage systems and catchment areas. Nitrate and phosphate are the major nutrient pollutants in local storm water runoff that may cause eutrophication. Various native plants were studied to determine their suitability for phytoremediation of nutrient pollutants in storm water runoff for application in bioretention systems. The plants showed different chlorophyll fluorescence and leaf greenness responses, as well as different biomass production. Nitrate and phosphare removal varied among different species, and hyperaccumulation was species dependent. Total dry biomass of tree species were strongly related to nutrient removal (p<0.01), whereas the total dry mass showed a significant relationship to flow rate in non-tree species (p<0.05).