Acceleration in dewatering water treatment plant sludges using covered drainage beds

• Grant number: 10/03139-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2010
• End date: February 28, 2011
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: João Sergio Cordeiro
• Grantee: Renan Felicio dos Reis
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The most of Water Treatment Plants (WTPs) for public supply in Brazil have used groundwater captation and complete cycle treatment system. In this treatment are included several steps, which are coagulation (usually using salts of iron or aluminum), flocculation, decantation, filtration and finally disinfection, pH correction and fluoridation. These procedures that the raw water is subjected, allow to generate a certain amount of waste (sludge) that varies mainly depending on the type and quantity of chemical added and the characteristics of the groundwater capted. This waste is found mainly in decanters and filters from WTP. Unfortunately, the most Brazilian WTPs throws its wastes directly into rivers, violating notes from Federal Law 9.605/98. There are natural and mechanized technologies to remove water from WTP sludge. Due to its fluid characteristic (1 to 5% of solids), treat this waste means to make it as solid as possible. Concerning about it, the drainage bed proposed by Cordeiro (2001) is one of the natural treatment technologies, which has basically two stages involved: drainage and evaporation. Its viability is already proven, but, seeking to get a better efficiency it has been proposed to make some tests with different geotextile blankets and conditioning the sludge with cationic polymer (improvement in the drainage stage), and placement of plastic cover (improvement in the evaporation stage). The proposed tests will be conducted in WTP from São Carlos-SP, managed by SAAE, where will be built two drainage beds, being one covered and one not. (AU)