Degradation of Organic Carbon in Pharmaceutical Wastewater: a Kinetic Approach

Author(s)

Izario Filho, Helcio Jose ^[1] ; Aguiar, Leandro G. ^[1] ; Siqueira, Adriano Francisco ^[2] ; Kondracki Alcantara, Marco Aurelio ^[2] ; Molgero Da Ros, Patricia Caroline ^[1] ; Rocha, Robson Silva ^[2] ; Santos Napoleao, Diovana Aparecida ^[2] ; Brandao, Joaquim Joffre ^[1]

Affiliation

^[1] Univ Sao Paulo EEL USP, Dept Chem, Escola Engn Lorena, Lorena, SP - Brazil

^[2] Univ Sao Paulo EEL USP, Dept Basic & Environm Sci, Escola Engn Lorena, Estrada Municipal Campinho S-N, BR-12602810 Lorena, SP - Brazil

• Document type: Journal article
• Source: WATER AIR AND SOIL POLLUTION; v. 232, n. 3 FEB 17 2021.
• Web of Science Citations: 0

Abstract

This study aimed to investigate the degradation kinetics of the total organic carbon (TOC) in real pharmaceutical wastewater. Because of the complexity of real wastewaters and the lack of knowledge on all reactions involved in their chemical degradation, the use of a kinetic approach becomes difficult. To overcome this difficulty, we adopted a kinetic model based on chemical equations validated for mechanisms of free radical generation. Photo-Fenton reactions were performed in a 1-L tubular reactor. The developed model satisfactorily described the degradation kinetics of TOC in wastewater, with an R-2 of 0.9997. The TOC degradation rate constant (k(d)) was estimated at 1 x 10(11) L-2 mol(2) s(-1), in agreement with literature values for the degradation kinetics of organic compounds. UV radiation had a positive effect on degradation, contributing to HO center dot formation. The adopted mathematical approach was highly sensitive to the formation rate constant of HO center dot from H2O2 (k(4)). By assuming the reaction to follow variable order kinetics (beta = 1 and beta = 2), it was possible to improve the goodness of fit of the model. Our results suggest, albeit in an incipient way, that the approach used in this study can be extended to the kinetic understanding of other complex wastewaters. (AU)

• FAPESP's process: 14/21364-3 - Study of degration to leachate through fenton and catalytic ozonation stochastic differential equation
• Grantee: Diovana Aparecida dos Santos Napoleão
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/02762-5 - Development of technologies to prevent pollution: degradation and monitoring online of antibiotics in sewage
• Grantee: Robson da Silva Rocha
• Support Opportunities: Research Grants - Young Investigators Grants