RO reject water contains high concentrations of salts and contaminants, making disposal
challenging. However, with proper treatment, reject water can be reused in various applications,
reducing wastage and promoting sustainability.
One effective approach is secondary RO treatment, where reject water undergoes additional
filtration to extract more usable water. Advanced membrane technologies, such as brine
concentrators and nanofiltration, enhance recovery rates.
Another strategy involves alternative reuse applications. RO reject water can be utilized for
industrial cooling, irrigation (if salinity is within acceptable limits), toilet flushing, and even
concrete mixing in construction. In some cases, reject water can be treated through
electrodialysis or ion exchange to extract valuable minerals like sodium and calcium.
Additionally, evaporation and crystallization methods can convert reject water into solid
waste, minimizing liquid discharge. This approach is particularly useful in Zero-Liquid Discharge
(ZLD) systems
