Streaming Potentials in Diatomite Filtration of Water

The purposes of this study were to: determine from streaming potential measurements the zeta potential of representative grades of diatomite used in water filtration; determine the effect of chemically treated water on the zeta potential of diatomite filter aids; and, determine the effect of electropositive materials used for coating diatomite on the zeta potential of coated filter aids. A smal1 acrylic plastic filter equipped with silver‐silver chloride electrodes was used as a streaming potential cell in this study. Streaming potentials were measured and recorded with a recording potentiometer that was connected across the two electrodes. Head losses were measured with a differential manometer containing bromoform for a manometer fluid. Filtration rates were indicated with a rotameter and were checked volumetrically during each filter run with a graduated cylinder as a check on the rotameter.