ReWater-DC Evo: A Three-Stage, Renewable-Assisted System for Recovering Data-Center Cooling Water

ReWater-DC Evo is a conceptual research proposal for recovering and reusing cooling-tower blowdown water from data centers, with particular relevance to the growing water demand associated with AI-driven computing infrastructure. The proposed system consists of three sequential treatment stages: electrical separation of heavy metals and suspended or dissolved contaminants; solar-assisted degradation of residual organic substances; and carbon-based reduction of dissolved salts. The staged architecture is designed so that upstream contaminant removal protects downstream treatment components from fouling and performance loss. This work provides a mathematical framework for water balance, recovery, reject concentration, contaminant removal efficiency, electrochemical treatment, photocatalytic degradation, carbon-based salt removal, and specific energy consumption. It also provides a proposed experimental protocol covering real and synthetic cooling-tower blowdown, analytical measurements, performance metrics, benchmarking against conventional treatment, and short-, medium-, and long-term testing. The approximately 95% water-recovery value presented in this work is a reported project potential and is not presented as a validated experimental result. The numerical examples and water-savings estimates are modelled under explicitly stated assumptions. Experimental validation, pilot deployment, long-term durability testing, reject-stream assessment, and techno-economic and life-cycle analysis remain necessary. The purpose of this preprint is to document the proposed ReWater-DC Evo architecture, its theoretical framework, and a reproducible pathway for future experimental validation.