ABSTRACT
Sulfate is a common contaminant, occurring widely in wastewater, waste, and potable water. The sulfate in water may be analyzed by ion chromatography, gravimetric method and turbidimetric method. Ion chromatography is suitable for measuring low concentrations of sulfate, at less than 1 ppm level. The lower limit of detection is about 0.1 mg/L. The gravimetric method is reliable only at a relatively high concentration range (>10 mg/L). The turbidimetric method is applicable in the concentration range of 1–40 mg/L. Samples with high sulfate concentrations may be accordingly diluted prior to analysis. Sulfate is precipitated as barium sulfate when added to barium chloride solution. Heavy metals interfere in the test by precipitating as sulfates, thus giving low results. Sulfates and bisulfates of alkali metals may occlude with BaSO4, yielding low results.
