Visible-light nano-photocatalytic aerogel for chloramine removal in water treatment
Sustainable nano-photocatalysts built from bismuth inorganic nanohybrids embedded in aerogel beads degrade chloramine under visible light. Designed as a scalable pre-treatment module for dialysis and other water systems, with silver-assisted chloride precipitation to meet stringent water quality targets.
Overview
This solution addresses the challenge of removing chloramine from water using a visible-light-activated photocatalytic system. Chloramine, a common disinfectant residual in municipal water, must be reduced to very low levels for sensitive applications such as hemodialysis. The proposed approach combines sustainable nanomaterials with bismuth-based inorganic nanohybrids embedded in aerogel beads to create a high-surface-area photocatalyst that operates under visible light, eliminating the need for UV sources. The system is designed as a compact, scalable unit process that can be installed upstream of dialysis equipment or other point-of-use water treatment systems.
Technical specifications
- Photocatalyst composition: Bismuth inorganic nanohybrids integrated within aerogels prepared from sustainable nanomaterials, providing high surface area and structural stability.
- Activation source: Visible light, enabled by engineered band-gap tuning of the bismuth-based photocatalyst.
- Reaction mechanism: Chloramine is reduced to ammonia and chloride ions under visible-light irradiation; chloride ions are subsequently precipitated by silver ions released from silver nanoparticles embedded in the aerogel matrix.
- System configuration: A packed column containing aerogel beads through which chloramine-contaminated water flows while being illuminated by visible light.
- Design advantages: Scalable unit process suitable for placement in front of dialysis equipment; avoids reliance on UV lamps and harsh chemical treatments.
Technology readiness level
The photocatalyst platform has been demonstrated at the laboratory scale. The research group has successfully prepared bismuth nano-hybrids embedded within sustainable aerogels and confirmed visible-light activation and degradation capability against various organic compounds. Ongoing and future work will focus on optimizing nanocatalyst loading, bead size, and composition; validating chloramine reduction performance in a packed-column flow configuration; and developing engineering process parameters to achieve a target effluent concentration of 0.1 mg/L chloramine. The technology is currently at an early-to-mid stage of development, transitioning from fundamental proof-of-concept toward engineered process design.
About University of Waterloo
University of Waterloo is a public research university in Ontario, Canada, known for an entrepreneurial, STEM‑driven culture. A globally recognized co‑op program places students with employers year‑round, creating direct talent pipelines and de‑risked pathways into sponsored research and contract development. An adjacent research and technology park hosts corporate R&D alongside faculty labs, and the campus sits within the Toronto–Waterloo innovation corridor for ready access to partners, investors, and scale‑up resources. Research is supported by competitive federal funding from Canada’s Tri‑Council agencies (NSERC, CIHR, SSHRC) and international programs. A creator‑owned IP policy and a dedicated tech transfer office enable flexible agreements, licensing, and spinouts.
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