Feed water quality total dissolved solids

A two- or three-stage RO system will usually remove about 96% to 98% of the total dissolved solids (TDS) in the water. The effluent water quality is generally high enough to send to low- to medium-pressure boilers without additional polishing. However, each application and feed water is different, and, therefore, water sampling and design projections should be conducted for every application to determine what the projected water quality will be (see Chapters 7 and 10). 

The program calculates total dissolved solids (TDS), conductivity, and the Langelier and Stiff-Davis Saturation Indexes (see Chapter 3.9). The screen allows the designer to use sodium, calcium, magnesium, chloride, sulfate, or bicarbonate to balance the water analysis. Water quality for up to five feed streams can be entered and blended together to make the total, combined feed water to the system. 

Total dissolved solids (TDS) in mg/1 or ppm is a measure of the total weight of impurities found in a water supply. The measure permits a quick, rough estimate of RO/NF permeate quality and feed pressure requirements. 

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