Dinking Water Production with a Dual Floating Medium-Sand Filter System

摘要

Low quality water supplies have been treated in a combined downflow filter column compristinga floating medium and a coarse sand layer at the bottom, the foucus being on a comparison of inorgain coagulants nad cationic polyelectrolytes as primary coagulants. In one study a commercially available organinc polyelectrolyte was not as effective as polyaluminium chloride, but an experimental organic polyemr have some aromatic and hydrophobic character was comparable iwth the inorgaince coagulatnt ofr particulates uptake, and was almost as good for orgnaics removal. In another comparison ferric chloride was less effective than highly charged organic polymers for turbidity removal. In both cases the dose of organic polymer reuqired was much less than that ofthe inorgnaic coagulant. This poses operational disadvantages of filter run length and sludge volume for the inorganic additives.