Optimized Water Supply in a Solar Evaporator for Simultaneous Freshwater Production and Salt Recycle

Solar desalination has shown great potential in alleviatingglobalwater scarcity. However, the trade-off between energy efficiency andsalt rejection remains a challenge, restricting its practical applications.In this study, we report a three-dimensional nitrocellulose membrane-basedevaporator featuring a high evaporation rate (1.5 kg m(-2) h(-1)) and efficient salt precipitation at the edges.Additionally, the salt is isolated from the photothermal area of theevaporator and falls automatically with a salt recovery rate of 97g m(-2) h(-1) in brine with 10 wt% salt content. The distinctive performance is attributed to the precisewater supply control, which was adjusted by changing the resistanceforce and driven force in the evaporator. With a high evaporationrate, stable performance, and specific salt recovery ability, thissolar evaporation structure holds great potential in water desalinationand resource recovery. Simultaneousmineral resource and freshwater collectionis fulfilled in hypersaline solution by a solar evaporator with anadjustable water supply flux, by which a stable salt collection rate(97 g m(-2) h(-1)) and high energyefficiency (93.97%) is achieved in 10 wt % hypersaline solution.

Automated summary

This study presents a three-dimensional nitrocellulose membrane-based evaporator with high evaporation rate and efficient salt precipitation, which shows great potential in solar desalination and resource recovery.