Treatment of Water by Direct Filtration

Abstract

The present study was performed in a pilot treatment system for synthetic turbid water with the all characterization and process. The parameters of the pilot unit were justified in the optimum conditions through the experimental work. For water treatment plants, filters are the most critical devices; so many studies have focused on improving these units ' quality. This can increase present plants ' capacity to meet the water consumption of the user. This work is therefore an attempt to improve the efficiency of filter operation by using pre-filtration coagulation and flocculation basins as it helps remove colloidal and thus improves the ability of the sand filter.

This study is aimed to investigate the influence of adding coagulant aids with alum on the performance of rapid sand filter , through experimented process by using  pilot plant (direct filtration) for operation condition of turbidity (150 NTU) and used different dose from alum alone and  with coagulant aid ( cationic polymer ) another one . Standard jar tests studies were conducted in order to determine the optimum doses of alum and polyelectrolyte It was found that the dose of alum (40 mg/l) and (0.8 mg/l) of polyelectrolyte at a pH of (7.52) are most appropriate.                            

Has been measurement influent and effluent turbidity from filter by using turbidity meters in order to determine efficiency of removal turbidity for all test and compared between the test for using alum alone and using alum with cationic polymer .The results indicated that that the maximum removal efficiency of turbidity 98% at filtration time (14hr) using coagulant (alum+polymer) and flocculation with direct filtration was the most efficient in term of turbidity.