Tech Manual Excerpt
Water Chemistry and Pretreatment Barium Sulfate Scale Prevention
Barium Sulfate Barium sulfate is the most insoluble of all alkaline-earth sulfates. When present in Scale Prevention water, it may lead to massive precipitation, possibly acting as a catalyst for calcium sulfate and strontium sulfate scaling.
In most natural waters, barium is present at a level that would cause barium sulfate precipitation in the concentrate stream. The critical feed concentration of barium may be as low as < 15 µg/L in seawaters, < 5 µg/L in brackish waters or even < 2 µg/L if sulfuric acid is dosed to brackish waters. Calculation /8/
Prediction of BaSO4 scaling potential is performed in the same way as the previously
described procedure for CaSO4.
1. Calculate the ionic strength of the concentrate stream (Ic) following the procedure described in Scaling Calculations (Form No. 45-D01551-en):
Eq. 1
2. Calculate the ion product (IPc) for BaSO4 in the concentrate stream:
Eq. 2
where: m 2+ 2+ ( Ba )f = M Ba in feed, mol/L m 2– 2– ( SO4 )f = M SO4 in feed, mol/L
3. Compare IPc for BaSO4 with the solubility product (Ksp) of BaSO4 at the ionic ≥ strength of the concentrate stream, Figure 1. If IPc Ksp, BaSO4 scaling can occur, and adjustment is required.
Adjustments for BaSO4 Scale Control The adjustments discussed in Calcium Sulfate Scale Prevention
(Form No. 45-D01553-en) for CaSO4 scale control apply as well for BaSO4 scale control.
Page 1 of 2 Form No. 45-D01554-en, Rev. 4 April 2020 Excerpt from FilmTec™ Reverse Osmosis Membranes Technical Manual (Form No. 45-D01504-en), Chapter 2, "Water Chemistry and Pretreatment."
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Page 2 of 2 Form No. 45-D01554-en, Rev. 4 April 2020