Novel bioretention system for nitrogen removal from urban stormwater runoff
A patented engineered soil media and bioretention system designed to remove nitrogen and other pollutants from urban stormwater runoff. The system combines optimized filter media with submerged zones and native plant species to achieve high removal rates of total suspended solids, total nitrogen, and total phosphorus.
Overview
Urban stormwater runoff carries significant amounts of pollutants, including nitrogen compounds, which are difficult to remove using conventional bioretention systems. This research proposes a novel bioretention system that integrates a patented engineered soil media with submerged zones and carefully selected native plant species to enhance nitrogen removal and overall water quality improvement. The system addresses the challenge of incomplete denitrification, which has historically limited the effectiveness of bioretention in removing inorganic nitrogen from stormwater.
Technical specifications
Key features:
- Patented engineered soil media composed of locally available materials with lower sand content
- Balanced saturated hydraulic conductivity of 100-300 mm/hr to optimize water quality improvement and detention depth
- Submerged zone design to support denitrification and remove inorganic nitrogen
- Integration of native plant species selected for their nitrogen removal performance
- Cost-effective use of locally available materials for filter media construction
Performance highlights:
- TSS removal: 90%
- Total nitrogen removal: 50%
- Total phosphorus removal: 85%
Technology readiness level
The technology has been validated at both lab and field scale, with demonstrated performance in pollutant removal and hydraulic conductivity. Future validation will involve column studies comparing conventional designs with submerged zone configurations, using the patented engineered soil media modified with cost-effective local materials. Native plants will be evaluated in chambers for their water quality performance, and selected species will be tested in the developed soil media to confirm their suitability for full-scale bioretention deployment.
About National University of Singapore
The National University of Singapore is a comprehensive public research university and the country’s flagship, known for a global, collaborative culture. Industry partners access co‑located corporate labs, shared core facilities, and an integrated academic health system that supports clinical translation at scale. Campuses border the one‑north and Singapore Science Park innovation districts, linking companies to deep‑tech startups, government research institutes, and multinational R&D hubs. Research is powered by competitive national funding from the National Research Foundation Singapore, A*STAR, and the Ministry of Education, alongside international consortia and industry‑sponsored programs. A dedicated technology transfer office and enterprise programs handle IP, licensing, and venture creation, offering streamlined engagement models, pilots, and access to talent.
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