The impact of coagulant PIX 113 modified by ultrasonic field on sewage sludge dewatering

摘要

Sewage sludge dewatering processes can be very costly and difficult to solve at the wastewater treatment plants all over the world. Sludge includes substances that do not dehydrate easily, and without initial proper preparation, the effects of its dehydration and the degree of separation are very low. The degree of dehydration of sewage sludge is significant, because it is associated with energy consumption and costs of drying the sludge. The aim of the research was to determine the influence of combined activity of PIX 113 coagulant (non-sonicated and sonicated) and Zetag 8160 polyelectrolyte on pressure filtration parameters of digested sewage sludge. A technique based on the preparation of coagulant PIX 113 with ultrasound waves was used in an unconventional way. The combination of physical and chemical sludge conditioning was intended to improve the sludge dewatering process. The sludge for tests was collected after the digestion process. The use of the non-sonicated and sonicated PIX 113 in combination with the polyelectrolyte Zetag 8160 resulted in a decrease of capillary suction time (CST) value in relation to CST of the untreated sludge. Applied dosages of chemical reagents, such as PIX 113 and Zetag 8160, have improved the values of final hydration of sludge in the process of pressure filtration. The lowest final hydration of sludge was obtained when sludge was prepared with sonicated PIX 113 and Zetag 8160. Thus, the use of ultrasonic wave for the modification of the PIX 113 coagulant improved results of sludge dewatering process during pressure filtration.