Modeling carbonate/bicarbonate and nitrate disturbance during secondary effluent disinfection by UV/H2O2 and UV/ozone

Author(s)

Cavalcante, Rodrigo Pereira ; Malvestiti, Jacqueline Aparecida ; Diogo Junior, Jose Paulo ; Dantas, Renato Falcao

• Document type: Journal article
• Source: WATER SCIENCE AND TECHNOLOGY; v. 86, n. 11, p. 20-pg., 2022-11-17.

Abstract

The disinfection of effluents has been considered the main step to inactivate pathogenic organisms to prevent the spread of waterborne diseases. The variation in the matrix composition can lead to the use of inadequate oxidant dose and disturb a correct treatment. The objective of this study was to develop a simple and practical mathematical model to simulate the disturbance of inorganic anions (CO32-/HCO3- and NO3-) during secondary effluent disinfection by UV/H2O2 and UV/O-3 . The pathogenic agents chosen for this study were total coliforms and E. coll. To build the mathematical model, a modification of the Chick model (referred to as 'Modified Chick Model') was proposed by employing a weighted average in the calculation of the kinetic constant. Both treatments were affected by the presence of the anions. However, with the highest NO3- concentration, less inhibition of disinfection was observed in the UV/H2O2 . The use of the arithmetic means to calculate the value of k as indicated by the Chick model, demonstrates a lesser precision in the prediction of the microorganisms concentrations. On the other hand, using the Modified Chick Model, a better prediction of the inactivation of the microorganisms was obtained, which can be confirmed by the validation performed. (AU)

• FAPESP's process: 22/00454-0 - Assessment of a multibarrier tertiary treatment for micropollutants removal from WWTP of São Paulo
• Grantee: Renato Falcão Dantas
• Support Opportunities: Regular Research Grants
• FAPESP's process: 22/04015-1 - Effects of oxidative treatments on microplastic pollution and its associated chemical and biological risks
• Grantee: Jacqueline Aparecida Malvestiti
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/03248-7 - Influence of secondary effluent composition on UV/O3 and UV/O3/H2O2 disinfection
• Grantee: José Paulo Diogo Junior
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 19/26210-8 - Investigation of the contribution of advanced oxidation processes in the multi-barrier treatment of biotreated effluents
• Grantee: Rodrigo Pereira Cavalcante
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/17774-1 - Influence of the secondary effluent composition on the disinfection by advanced oxidation processes
• Grantee: Renato Falcão Dantas
• Support Opportunities: Research Grants - Young Investigators Grants