A case study for process optimization of direct filtration in Korea

In the case of S water treatment plant, it was designed to be mostly operated by direct filtration mode all the year round. To evaluate the conditions of such operation mode, in this study, we operated pilot plant by direct filtration process by making flocculation treatment water flow into anthracite filter and active carbon (Calgon, Norit) filter which is an assembly of deep bed filter paper, and studied to find out the principle in which turbidity is removed in filter paper by measuring turbidity and head loss by the depth of filter, and an appropriate operation method. Also we conducted comparison evaluation according to kinds of coagulant and evaluation according to the injection of a polymer coagulant, a filter aid, before letting filter flow into flocculation treatment water. On the basis of the optimum operation of direct filtration process using deep bed filtration, it is necessary to decide and inject the optimum injection volume of filter aids taking account for the quality of raw water and to operate anthracite filter, which will also contribute to lowering the operation expenses of a filtration plant and improving the quality of treatment water.