Enhanced Coagulation on Reservoir Water by Dual Inorganic Coagulants

Abstract

This study evaluated the effect of enhanced coagulation on reservoir water using Al₂(SO₄)₃, PACl, FeCl₃, and PFS as coagulants. The treatment efficiencies were evaluated by the removals of soluble organic matter, turbidity, and bacteria. PFS was found to give better dissolved organic carbon (DOC) removal with less residual iron than FeCl₃. Al₂(SO₄)₃ performed best in removing turbidity, color, and bacteria, but was not, however, effective in DOC removal. When Al₂(SO₄)₃ and PFS were combined, the best improvement in water treatment was achieved when PFS was added at the start of the rapid mixing and the Al₂(SO₄)₃ was added sometime during the last 30 s of the rapid mixing. It was also discovered that a combination of high dose of PFS and low dose of Al₂(SO₄)₃ gave efficient enhanced coagulation.