Green filter granules from water treatment residuals for nutrient removal
Patented green filter granules made from aluminum-based water treatment residuals (WTR), an industrial byproduct, offer a low-cost, sustainable solution for removing nitrogen and phosphorus from water and stormwater runoff. Leveraging high-surface-area amorphous Al oxides, these porous granules capture nutrients via adsorption and promote denitrification in micro-anoxic zones, addressing eutrophication and water quality challenges.
Overview
This technology transforms aluminum-based water treatment residuals (WTR), an industrial byproduct from drinking water treatment, into patented green filter granules that remove nitrogen and phosphorus from water. By repurposing a waste stream into a high-performance filtration media, the granules offer municipalities, stormwater managers, and water treatment operators a sustainable, cost-effective alternative to conventional nutrient removal materials. The granules are currently being field-tested as catch basin filters in a parking lot for urban stormwater runoff treatment.
Technical specifications
- Material source: Aluminum-based water treatment residuals (WTR), a byproduct of drinking water treatment processes
- Active components: Amorphous aluminum oxides and hydroxides that provide high specific surface areas and abundant sorption sites
- Phosphorus removal mechanism: Inner-sphere complex formation between phosphate ions and Al³⁺ at the granule surface
- Nitrogen removal mechanisms: Ammonium adsorption onto Al hydroxide active sites and denitrification promoted within porous micro-anoxic zones that trap moisture inside granules
- Physical structure: Porous granules engineered to overcome the low hydraulic conductivity of raw WTR
- Target performance: Ammonium, nitrate, and phosphate removal validated through sorption isotherm, kinetic, and column studies at a treatment flow rate of 2 gpm per square foot
- Field validation: Currently deployed as catch basin filter materials in a parking lot for urban stormwater contaminant removal
Technology readiness level
The granules are patented and have been validated in laboratory settings through sorption isotherm, adsorption kinetics, and column studies for phosphorus and metal removal. The research team has two decades of experience studying WTR properties and pollutant removal performance. Current field testing in a parking lot catch basin application is providing real-world stormwater runoff data. A planned 6-month proof-of-concept project will complete additional laboratory validation for ammonium, nitrate, and phosphate removal under dynamic flow-through conditions, advancing the technology toward broader commercial deployment.
About Stevens Institute of Technology
Stevens Institute of Technology is a mid-sized, STEM-focused private research university in Hoboken, New Jersey, known for industry‑aligned education and applied research. Corporate partners engage through a co‑op program, sponsored research, and access to specialized labs and test facilities minutes from Manhattan. A dedicated corporate relations team and streamlined contracting help scope projects quickly, while an incubator and entrepreneurship programs link faculty expertise to venture pathways. Research is supported by competitive federal funding from agencies such as the National Science Foundation, the Department of Defense, the Department of Energy, and the National Institutes of Health. A technology transfer office provides IP strategy, licensing, and startup support.
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