RO REJECT WATER TREATMENT
1. Almost 30-45% water is rejected from an RO system. The increase in TDS percentage in reject water will be
somewhere close to 33% higher than the input TDS. The reject water from an RO system is fed
directly into a 2nd RO unit to reduce the quantity of reject water. The
reject of the second RO is thermally evaporated or treated by root zone technology.
2. REUSE: Most reject water, with a TDS level of 1200 - 1500 PPM
can be safely used for car washing, flushing toilets , gardening etc.
3. ROOT ZONE TECHNOLOGY: If there is land available, we can use
this water selective plantation suitable for high TDS after pH correction.
The reject water from RO is subjected to root-zone technology applying
sacrificial plants typha-reeds or cayhna-indica etc. Only plants can use the in
organics. This is how Nature is designed. The remedied water can then be
used for other grass/ greens/Irrigation.
4. Thermal Evaporation: Evaporation is a time-tested methodology for
reducing the water portion of water-based waste. The evaporator converts the
water portion of water-based waste to water vapor, while leaving the higher
boiling contaminants behind. Thermal Evaporator heated by natural gas or
other available heat sources like boiler steam can evaporate water to atmosphere
very effectively. Multiple effect evaporators
are costly and energy guzzling.
5.RO reject water should never be added to ETP water or rain water harvesting system.
