Nutrient recovery from urban stormwater runoff using magnesium carbonate pellets
A novel adsorbent technology using magnesium carbonate pellets to recover nitrogen and phosphorus nutrients from urban stormwater and municipal wastewater. Achieves over 78% ammonia-nitrogen and 75% ortho-phosphate recovery, offering a sustainable approach to nutrient management and water quality improvement.
Overview
This technology presents a magnesium carbonate-based adsorbent system designed to recover valuable nutrients, specifically nitrogen and phosphorus, from urban stormwater runoff and municipal wastewater. The approach addresses two critical environmental challenges simultaneously: reducing nutrient pollution in water bodies and recovering finite nutrient resources for potential reuse. By enabling separation and concentration of nutrients into a contaminant-free, nutrient-rich resource, this solution supports circular economy principles in water management.
The pellets demonstrated over 78% recovery of ammonia-nitrogen (from 11.0 mg/L concentrations) and 75% recovery of ortho-phosphate (from 3.3 mg/L concentrations) from municipal wastewater. With increasing regulatory pressure to reduce nutrient levels to ultra-low targets, this technology offers a scalable pathway to meet stringent water quality standards while creating value from recovered nutrients.
Technical specifications
Key features:
- Magnesium carbonate pellets synthesized with cellulose binder (0–20% weight ratios) and calcined to enhance internal surface area
- Pseudo-second-order kinetic model indicates chemisorption-driven nutrient capture
- Langmuir isotherm behavior confirms monolayer adsorption with high affinity for target nutrients
- Average adsorption capacity of 40–100 mg of nitrogen and phosphorus per gram of MgCO3 pellets (optimized at 15% cellulose content)
- Selectivity for nutrient ions enables separation from other contaminants
- Material characterization using BET surface area analysis, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy
Performance targets:
- Designed to reduce nutrients to ultra-low levels (below 3 mg/L for nitrogen and 0.1 mg/L for phosphorus)
- Continuous flow reactor operation at 1 gallon per minute per square foot
- Long-term validation planned over 6–9 month operational periods
Technology readiness level
The technology has progressed through laboratory-scale validation using municipal wastewater, demonstrating consistent nutrient recovery performance across multiple experimental conditions. Future validation efforts will focus on fabricating multiple form factors including beads, tablets, and pellets to optimize pore size distribution, surface area, and adsorption capacity. The research team plans to test the pellets in continuous flow-type reactors under realistic stormwater conditions and evaluate physical and chemical stability over extended periods. Additional work is needed to scale production, validate long-term performance with variable stormwater chemistry, and assess the economic feasibility of nutrient recovery at full scale.
About University of Cincinnati
The University of Cincinnati is a comprehensive public research university with an applied, urban-serving character and a significant clinical enterprise. Industry engages through one of the nation's largest cooperative education programs, placing students year-round with corporate R&D and operations teams and creating an on-ramp to sponsored research. An innovation district near campus hosts co-located corporate labs, startup space, and shared prototyping facilities, while the university's integration with a major hospital system enables clinical studies and translation. Research is supported by competitive federal funding from agencies such as NIH and NSF, along with state and industry partnerships. A dedicated technology transfer office manages IP, licensing, corporate agreements, and startup formation, providing flexible models for collaboration.
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