ASTM D4328

This practice covers the mathematical calculation of the supersaturation of three principal sulfate scaling compounds found in industrial operations. Application of this standard practice to the prediction of scale formation in a given system, however, requires experience. The calculations tell the user if a water, or mixture of waters, is in a scaling mode. Whether or not scale will in fact form, how quickly it will form, where it will form, in what quantities, and what composition are subject to factors beyond the scope of this practice. However, based on how supersaturated a given water or mixture of waters is, an objective evaluation of the relative likelihood of scale formation can be made.

Note 1—There are several personal computer (PC) type programs that are both available commercially and publicly that will perform these calculations.

1. Scope

1.1 This practice covers the calculation of supersaturation of barium sulfate, strontium sulfate, and calcium sulfate dihydrate (gypsum) in brackish water, seawater, and brines in which barium, strontium, and calcium ions either coexist or exist individually in solution in the presence of sulfate ions.

1.2 This practice is not applicable for calculating calcium sulfate dihydrate supersaturation if the temperatures of saline waters under investigation exceed 95°C. At temperatures above 95°C, hemianhydrate and anhydrite would be major insoluble forms.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents

D 1129 Terminology Relating to Water
D 1192 Specification for Equipment for Sampling Water and Steam in Closed Conduits
D 3352 Test Method for Strontium Ion in Brackish Water, Seawater, and Brines
D 3370 Practices for Sampling Water from Closed Conduits
D 3561 Test Method for Lithium, Potassium, and Sodium Ions in Brackish Water, Seawater, and Brines by Atomic Absorption Spectrophotometry
D 3651 Test Method for Barium in Brackish Water, Seawater, and Brines
D 3986 Test Method for Barium in Brines, Seawater, and Brackish Water by Direct-Current Argon Plasma Atomic Emission Spectroscopy
D 511 Test Methods for Calcium and Magnesium in Water
D 512 Test Methods for Chloride Ion in Water
D 513 Test Methods for Total and Dissolved Carbon Dioxide in Water
D 516 Test Method for Sulfate Ion in Water

Index Terms

barium sulfate; brines; calcium sulfate dihydrate; strontium sulfate; Barium sulfate (BaSO4); Brackish water/brines; Calcium sulfate (CaSO4); Saturation; Seawater (natural/synthetic); Strontium sulfate (SrSO4); Supersaturation; ICS Number Code 13.060.30 (Sewage water)

Citing ASTM Standards

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