Improvement of removal efficiency of water supply plant by using polyelectrolyte type LT-22 with alum

Abstract

Abstract This study examined the effect of using the industrial coagulant of Polyelectrolyte type LT-22 and comparing it with the use of alum. A series of Jar tests were performed on raw water of 10, 20, 40, 60, and 80 Nephelometric Turbidity Units (NTU) using different doses of alum and fixed doses of industrial coagulant of Polyelectrolyte. The final turbidity and pH were measured after sedimentation. The results showed that the use of the Polyelectrolyte with alum is better than the use of alum alone, and adding of the Polyelectrolyte to alum is more effective at 80 NTU, as compared with the use of alum alone. The results of using the Polyelectrolyte with alum gave similar results when using the alum alone at 10 NTU. The rate of decrease in pH when using the polyelectrolyte with alum was higher than when using alum alone. The use of the Polyelectrolyte with alum also created clear large-sized flocculants that are easy to settle at the end of the slow mixing period, that is, after 30 min.