Evaluation of UASB reactor hydraulic detention time variation and its interference in denitrification process in continuous flow system

• Grant number: 19/25630-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): February 01, 2020
• Effective date (End): August 31, 2020
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Luiz Antonio Daniel
• Grantee: Mário Berni de Marque
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Anaerobic sewage treatment has advantages due to low sludge production, low implementation and operation costs and long cell retention times with short hydraulic detention times. However, it is ineffective in removing nutrients such as nitrogen, requiring other forms of treatment to comply with legislation when the final disposal of effluent. One of the forms of biological nitrogen removal is through the nitrification and denitrification process in aerobic and anaerobic environments, respectively, using ammonia as an electron donor and oxygen as the final electron receptor in nitrification and, in denitrification, the organic matter that produces nitrogen. donates electrons to nitrate, which is the ultimate receptor, where the ratio of carbon to nitrogen (C / N) may favor or disfavor such a process. Thus, studies are needed to evaluate the carbon and nitrate relationship in subsequent anoxic reactors of anaerobic treatments (such as anaerobic sludge blanket reactors - UASB), which promote heterotrophic denitrification. In this case, the carbon source comes from the residual organic matter in the UASB reactor effluent that can be changed by varying the hydraulic detention time (TDH) in the reactor. Thus, this work aims to evaluate, in a continuous system, different TDHs for an anaerobic reactor that favors denitrification in an anoxic reactor with aerobic reactor effluent recirculation, having nitrate as electron receptor for its reduction to gaseous nitrogen, that of the effluent. (AU)