Solar-driven ion-Rejecting evaporator enables continuous zero liquid discharge from hyper-saline wastewater

Hyper-saline wastewater represents a growing environmental and industrial challenge, yet current zero liquid discharge (ZLD) technologies remain energy-intensive, prone to fouling, and economically unsustainable. Here we report a solar-powered ion-rejecting water-activation vapor evaporator (iWAVE) that enables continuous ZLD with simultaneous recovery of high-purity water and crystalline salt. The system integrates a star-polyelectrolyte complex (sPEC) layer that maintains its internal ion concentration below 35% of saturation, suppressing interfacial crystallization while accelerating water diffusion and evaporation through multiscale disruption of the hydrogen-bond network. Under saturated brine feeds, the iWAVE achieves ultrahigh evaporation rates (>7.8 kg m-2 h-1) and >95% recovery of both water and salt, with stable outdoor operation over two months. Techno-economic analysis and life-cycle assessment show reduced electricity consumption (~92%) and greenhouse gas emissions (~77%) compared with reverse osmosis-based ZLD. The iWAVE enables a low-maintenance, scalable pathway for treating diverse saline wastewaters, advancing the practical implementation of solar-powered circular water systems.