The Feedwater must normally be pretreated to ensure optimum membrane
performance and reduce maintenance requirements.
The Feedwater enters the first stage where a portion of the water is purified
(permeate). The remaining (concentrate) becomes the second stage feed and
so on . [EBD Water design is optimized at 2 to 3 stages].
The concentrate from the last stage is directed to drain. The permeate streams
from all stages are collected in one manifold for a total system recovery of
50 - 85% (depending on Feedwater quality and system capacity).
The total system salt rejection varies, depending on such items as the type
and age of elements, the system recovery, and other factors. Typically,
rejection of 80 - 99% of the TDS and 90 - 99% of the suspended material
(organics and microcontaminants) can be realized by Brackish Water Systems.