Infrared Turbidimetric Titration Method for Sulfate Ions in Brackish Water

In this work an infrared turbidimetric titration method is described for the determination of sulfate ions in brackish water. A suspension of barium sulfate is produced in an aqueous solution and/or brackish water sample by the addition of barium chloride solution and the turbidity is monitored with the help of an immersed infrared sensor. The developed sensor utilizes an optical system to measure the evolution of turbidity during the titration. This sensor is a simple device designed in the laboratory, consisting of two infrared diodes (LED), the first is an emitter and the second is used as detector (receiver). The data acquisition system is made with the help of a dataloger made on the basis of the microcontroller 16F877/874 accompanied with adaptable software both of them are self made. Concentration over 60 μg/mL of sulfate expressed as, SO42- can be measured with high reproducibility, by this method without a preliminary treatment or dilution of the sample. The method determines SO42 - concentration of brackish water with RSD of < 1.2%.