EFFECTIVENESS OF NATURAL POLYELECTROLYTES IN WATER-TREATMENT

Synthetic Polyelectrolytes are widely used in the United States because of their effectiveness as a coagulant or coagulant aid. Synthetic polyelectrolytes produce a lower volume of sludge compared with alum flocculation, and their effectiveness is not much affected by the pH level of water. Synthetic polyelectrolytes provide better dewatering characteristics in sludge produced and facilitate better filter performance. However, one drawback of these products is that their long-term effects on human health are not well understood. Natural polyelectrolytes such as chitosan (cationic) and sodium alginate (anionic) are not only as effective as or even more effective than their counterparts at similar dosages, but they also do not cause any adverse effects to human health. This article presents results of bench- and pilot-scale tests that compared natural and synthetic polyelectrolytes. It suggests that natural products would be workable substitutes for synthetic products.