Solar Desalination

News: IIT Bombay scientists developed Dual-Sided Superhydrophobic Laser-Induced Graphene (DSLIG) evaporator for solar-based desalination.

Freshwater Scarcity: Addresses global freshwater scarcity by improving desalination technology. Current freshwater readily available <0.05%.

DSLIG Features:

• Solar & Electric Heating: Uses both solar and Joule (electric) heating for consistent desalination, even with fluctuating sunlight.
• Superhydrophobic Surface: Repels water (lotus leaf effect), preventing salt deposition and maintaining efficiency.
• Material Composition: Polyvinylidene fluoride (PVDF) for hydrophobicity and poly (ether sulfone) (PES) for mechanical stability.

Significance: Environmentally sustainable alternative with low carbon footprint and high efficiency for treating industrial wastewater and saltwater discharges.

Desalination Importance: Removing salt from seawater/brackish water for human consumption, irrigation, etc. Brine management is a critical challenge.

Interfacial Evaporation: DSLIG is an interfacial evaporation system where an evaporator material absorbs solar energy and heats up a thin layer of water. This localized heating minimizes heat loss and enhances the desalination process efficiency.

DSLIG Benefits: Combats solar fluctuation issues and salt deposition. Electric heating compensates for lack of sunlight, superhydrophobic surface resists salt build-up. Can treat concentrated salt solutions.

Material Production DSLIG by coating a layer of PVDF on one side of a thin layer of another polymer LIG, PES. Graphene was then engraved on the PVDF polymer side of the material using laser-based engraving technology.

Future Steps: Further field testing is required before large-scale applications can be made