Water purification with two stage thickening of sludge

摘要

Water treatment is carried out in two parallel or separate settlers. One of the settlers is lamellar and produces thickened sludge, and coagulants or flocculants may be added. The other uses fine sand ballast and produces a non-thickened, weighted sludge which is transferred to the settler-thickener to further concentrate the sludge before final treatment.