Expected water quality outcomes
Solar desalination can produce a range of water qualities depending on the technology and treatment steps used. It can meet standards for drinking water and agricultural use when systems include appropriate design, pre-treatment, and post-treatment.
Drinking water:
- Reverse osmosis (PV-RO) can reduce salts, pathogens, and many chemical contaminants, producing potable water that meets WHO and national standards when properly sized and maintained.
- Thermal distillation produces very low-salt water and effectively removes most microbes and many organics, though volatile compounds may need additional treatment.
Irrigation water:
- Desalinated water for irrigation can be tailored to crop salt tolerance. Lower-cost treatment may be acceptable for certain crops; however, complete desalination is best when soil salinity risks exist.
Common post-treatment steps include:
- Remineralization to add back beneficial minerals for taste and corrosion control
- Disinfection (UV, chlorination) for microbial safety
- Adjustment of pH and alkalinity for distribution or irrigation compatibility
Key considerations:
- Regular monitoring is essential to ensure continued compliance with health and agricultural standards.
- Brine disposal must be managed to avoid local salinization of soils or ecosystems.
- System maintenance (membrane cleaning, condenser upkeep) affects long-term water quality.
With proper design and operation, solar desalination can reliably produce safe drinking water and irrigation supplies in many contexts.