PREDICTION OF GYPSUM SOLUBILITY AND SCALING LIMITS IN SALINE WATERS

Gypsum solubility in natural seawater and agricultural drainage water was measured at temperatures between 25 and 70 °C. Solubilities at higher ionic strengths were also measured in natural water samples augmented with magnesium chloride. Scaling thresholds were evaluated graphically from solubility data. These results were compared with calculated values based on various computation models. A computation scheme based on extended Debye-Hiickel theory was used as the basis for this work. The computer program finally developed in this paper provides read out of solubilities as well as scaling thresholds for gypsum. The program is practical for engineering use showing a variation of less than 5 % from experimentally derived values. © 1979, American Chemical Society. All rights reserved.