Low‐dosage high‐rate direct filtration

Abstract

Direct filtration of public water supplies is an increasingly acceptable treatment option. Compared with conventional treatment, direct filtration has lowered capital costs, reduced space requirements, and decreased sludge quantities. Moreover, the direct filtration process may offer large reductions in coagulant dosages and costs. The authors’ review of their experience with the use of low‐dosage chemical treatment in preparation for direct filtration, as well as a literature review, provides evidence that the potential for low‐dosage treatment may be widespread.