Effect of cooling and cover material on the performance of a solar humidification-dehumidification system used for brine concentration

As a response to the growing global demand for sustainable water recovery technologies, this study evaluates a solar-driven humidification-dehumidification system for brine concentration and water recovery. The system integrates two external cover materials – polycarbonate and acrylic – with different cooling configurations: copper tube heat exchangers, thermoelectric Peltier plates, and their combination. A real reverse osmosis brine with total dissolved solids of 73.6 g/L was used as the feed solution. The performance of the system was assessed through the gained output ratio (GOR) and condensation performance (CP). The highest GOR (5.55) and CP (1.16) were obtained using acrylic covers and a combined copper tube–Peltier configuration. The crystallized salts were rich in minerals of economic and industrial importance. In this work, the feasibility of recovering valuable minerals and water has been demonstrated at a pilot-plant scale, which is of particular interest in areas with severe water shortages. This offers potential for resource recovery in the context of zero liquid discharge, contributing thus to circular economy strategies in desalination, and offering an alternative that allows brine to be discharged into natural waters, thus avoiding its potential environmental impact.