APPLICATION AND COST ANALYSIS OF SLUDGE DRYING TECHNOLOGY: CASE STUDY IN A MUNICIPAL WASTEWATER TREATMENT PLANT

摘要

This paper evaluated the operation statue of two-phases sludge drying technology (Innoplana dry 2E) from both the technical and economic aspect. The tested equipment was one part of sludge treatment process in La Test du Buch wastewater treatment plant (WWTP), located at the south west of France and adjacent to the Atlantic. This WWTP produced 5.5.7.5 tons of sludge (dry basis, t-ds) per day which were supposed to be treated by the drying technology. The results showed that the drying technology had a significant economic advantage. The treatment costs by sludge drying in winter and summer were 217€/t-ds and 155€/t-ds, respectively, accounting for 53% and 38% of the cost that the dewatered sludge was transported out for the further treatment.During the tourist season (i.e.Jul.and Aug.), the sludge amount exceed the treatment capacity of the drying equipement, while at the off season, the uptime for the equipement was insufficient mainly due to the clogging of screens. The solution for this problem may be controlling the drying temperature, adjusting the replacement frenquency of screens and assuring the normal operation of sewage treatment facilities.