Nutrient removal and plant biomass of 5 wetland plant species in Singapore

Abstract

Five native plant species (Typha angustifolia, Scirpus mucronatus, Lepironia articulata, Eleocharis dulcis and Phragmites karka) were investigated for their nutrient removal efficiencies in shallow pond systems in Sg Buloh Wetland Reserve with water depth 0.12-0.30 m of a total 160 m2 in area size. The project aimed to investigate nutrient removal rates, removal efficiencies, nutrient storage in plant biomass, and plant growth. Pond water quality before and after planting in fully vegetated ponds improved significantly at 24.4% TP and 64.4% TN reduction in Pond 6. Scirpus mucronatus, Typha angustifolia, Lepironia articulata and Eleocharis dulcis showed high growth rates. Phragmites karka showed low growth rate due to pest attack by aphids. Nutrient concentration in stem/leaf samples of the 5 species were within the ranges of 1% to 3% of dry weight for nitrogen and 0.1% to 0.3% of dry weight for phosphorus. Average daily mass removal rates ranged from 3.5-9.6 kg P ha−1 day−1 and 13.5-33.5 kg N ha−1 day−1. This field trial showed that the 4 species Lepironia articulata, Eleocharis dulcis, Typha angustifolia and Scirpus mucronatus are suitable species in surface flow wetland or shallow pond systems for nutrient removal in tropical environments.

The Use of Constructed Wetland for Mitigating Nitrogen and Phosphorus from Agricultural Runoff: A Review

“…Wetlands planted with Iris pseudacorus testified drops of TN, NH4-N, and TP by 39.47%, 84.65%, and 26.28%, respectively, after an overall hydraulic residence time of four months [97]. Likewise, Eleocharis dulcis also showed the removal of TN and TP by 64.4% and 24.4%, respectively [103]. Apart from the most common emergent plants reviewed above, researchers also recommended Eleocharis dulcis, Typha angustifolia, and Scirpus mucronatus as the optimum plant species in surface flow wetlands [103].…”

“…Likewise, Eleocharis dulcis also showed the removal of TN and TP by 64.4% and 24.4%, respectively [103]. Apart from the most common emergent plants reviewed above, researchers also recommended Eleocharis dulcis, Typha angustifolia, and Scirpus mucronatus as the optimum plant species in surface flow wetlands [103].…”

“…Some researchers have compared the removal efficiencies of N and P between different species in the same conditions. For example, Sim et al [103] ranked four common emergent plant species on the P removal (Eleocharis dulcis > Scirpus mucronatus > Typha angustifolia > Phragmites karka) and TN removal (Eleocharis dulcis > Typha angustifolia > Scirpus mucronatus > Phragmites karka). In addition, Wu et al [97] compared the removal efficiencies of TN, NH4 + -N, and TP by Typha orientalis, Iris pseudacorus, Phragmites australis, and Scirpus validus.…”

How Waterlogged Conditions Influence the Nitrogen Dynamics in a Soil–Water–Plant System: Implications for Wetland Restoration

“…Plants offer an added benefit to wetland restoration and are effective in mitigating wetland eutrophication by absorbing, assimilating, and reutilizing nutrients such as nitrogen and phosphorus in the water body and sediment to support their own physiological processes and growth for the following year [15][16][17][18][19][20]. Wetland plant roots share some common characteristics, such as providing oxygen and secreting oxygen to form aerobic, facultative and anaerobic micro-environments around the rhizosphere, thereby promoting the degradation of pollutants in sewage by microbial nitrification and denitrification [21].…”