Electrodialysis reversal system for cost-effective water hardness reduction in dialysis applications
A novel electrodialysis reversal (EDR) technology designed to reduce hardness in municipal or well water supplies for dialysis use. Leveraging novel stack designs and operation methods, the system achieves over 90% water recovery, 55% lower capital costs than traditional EDR, and higher energy efficiency than reverse osmosis for small-to-medium scale water treatment.
Overview
This solution applies electrodialysis reversal (EDR) technology to reduce hardness in municipal or well water sources to meet the stringent quality requirements of dialysis systems. Prior research demonstrated that EDR outperforms reverse osmosis (RO) and distillation in small-scale (1–10,000 L/day) potable water production by achieving higher water recovery (>90%), greater energy efficiency, and lower maintenance demands. Novel stack designs and operation methods have driven capital cost reductions of approximately 55% compared to traditional EDR systems. The technology is being adapted to target hardness reduction at flow rates of 100–1,500 mL/min, addressing a critical water purification challenge for dialysis in resource-limited and decentralized care settings.
Technical specifications
- Core technology: Electrodialysis reversal (EDR) using ion-selective membranes and polarity reversal to mitigate scaling and fouling
- Target flow rates: 100–1,500 mL/min, suitable for individual dialysis machines and small clinic deployments
- Feed water compatibility: Tested with total dissolved solids (TDS) of 1,000–3,000 mg/L and hardness levels at or above typical dialysis requirements
- Water recovery: Greater than 90%, minimizing wastewater volume
- Capital cost reduction: Approximately 55% lower than conventional EDR designs through novel stack architecture and operation methods
- Energy efficiency: Lower energy consumption than reverse osmosis for comparable small-scale applications
- Maintenance: Reduced maintenance burden relative to RO, supporting reliable operation in limited-resource environments
- Integration potential: Designed to leverage existing dialysis system pumps and DC power supplies to streamline deployment
Technology readiness level
The technology has progressed through theoretical simulations, controlled laboratory experiments, and pilot-scale field studies at both home-scale (~12 L/day) and community-scale (~10,000 L/day) production levels. While hardness was not the primary contaminant targeted in earlier studies, all pilot feed waters exhibited hardness at or above relevant levels, providing preliminary validation of the technology's capacity to address this challenge. Next steps include refining technical specifications such as allowable output concentrations, human interaction requirements, and integration with existing dialysis hardware. System optimization will identify Pareto-optimal design points balancing membrane area (capital cost) against energy use (operating cost), followed by experimental validation at a mutually selected design point using representative feed water.
About University of Minnesota
The University of Minnesota is a flagship, comprehensive public research university spanning multiple campuses, with a large research enterprise and clinical integration. Industry engages through co-located labs on the Twin Cities campuses, access to an academic health system for clinical translation, and pilot and field-testing facilities that speed scale-up. A statewide extension network and outreach centers provide real-world sites and data partnerships across Minnesota, while proximity to a dense medtech and Fortune 500 corridor enables frequent collaboration. Research is supported by competitive federal funding, including NIH, NSF, DOE, USDA, and DoD. A dedicated technology transfer office manages IP, licensing, sponsored research agreements, and startup incubation to speed commercialization.
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