Parker AQUA DUO - A455C, Technical Manual

Page: 36 / 81

36
35,000 ppm (parts per million) TDS, although variations of 5000 ppm are common in various parts of the
world. The fundamental goal any desalination process is a significant reduction in the number of
dissolved solids in water.
Figure 3.2: Simplified Schematic of a RO System
It should be noted that no system can remove all the dissolved solids from seawater. The system is
designed to reject approximately 99% of the TDS or, in other words, to allow 1% of the 35,000 ppm
TDS in the seawater to pass into the product water. This yields water of less than 500 ppm, the
recommended TDS for drinking water. A system such as this is said to have a salt passage
percentage of 1% or a salt rejection of 99%.
3.2 PRODUCT WATER QUALITY STANDARDS
This RO unit will produce permeate (product water) with a quality of < 500 ppm TDS and in
accordance with World Health Organization (WHO) standards for drinking water. General specifications for
acceptable drinking water quality are as follows:
Constituent Ion/Molecule Maximum Limits (ppm)
Nitrate 10
Fluorine .1
Sulfate 100