Surface Water Treatment (Jar Test)

What is a Jar Test?

  • Jar tests are used in water treatment to determine the optimum dose of a coagulant. The most common;y used coagulant is ALUM.

  • Results of the test are dependent on current raw water quality, which may vary day-to-day

  • The apparatus is operated to stimulate a mixing, flocculation and settling cycle.

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Optimum Dosage

  • Varying amounts of coagulants are added at the same time to the jars that contain water to be treated.

  • After rapid mixing, the turbidity in each jar is measured and plotted against the coagulant dose.

  • The optimum ALUM dose is determined by this plot.