Tandem anaerobic-aerobic degradation of ranitidine, diclofenac, and simvastatin in domestic sewage

Author(s)

da Silva, Thiago H. G. ^[1] ; Furtado, Rafaely X. de S. ^[1] ; Zaiat, Marcelo ^[2] ; Azevedo, Eduardo B. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Chem, CP 780, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Sao Carlos Sch Engn, CP 780, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Science of The Total Environment; v. 721, JUN 15 2020.
• Web of Science Citations: 0

Abstract

There is a consensus among scientists that domestic sewage treatment plants are the main sources of drugs entry into the aquatic environment. Therefore, this work studies the biodegradation of the drugs ranitidine (RNT), diclofenac (DCF), and simvastatin (SVT) (50 mu g L-1, each), in real domestic sewage, using a continuous anaerobic-aerobic reactor with immobilized biomass and an anaerobic batch reactor. The continuous anaerobic-aerobic reactor was operated for 6 months with hydraulic retention time (HRT) of 8 h. The initial degradation rates and the maximum oxidation capacities (MOC) of the system were estimated, achieving 90, 72, and 62% removals and 100, 93, and 72% of MOC for RNT, DCF and SVT, respectively, as well as 71% removal of soluble chemical oxygen demand (COD). RNT was degraded throughout the reactor, while DCF was degraded mainly in the two anaerobic chambers and SVT in the first anaerobic chamber. Anaerobic batches were used for the identification of biodegradation by-products (2,6-dichloro-N-(2-methylphenyl) aniline and simvastatin acid), the evaluation of the specific methanogenic activity (SMA) inhibition, and the estimation of acute and chronic ecotoxicities using the ECOSAR 1.11 software. The present study showed that, even at environmental concentrations, RNT, DCF, and SVT were capable of inhibiting the SMA. Lipophilicities dictated the behavior of those three drugs. The greater their lipophilicities, the greater the SMA inhibition and their ecotoxicity. (C) 2020 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 12/09569-3 - Coupling between biological and advanced oxidative processes for treating sanitary wastewater: pharmaceuticals degradation and safe reuse
• Grantee: Thiago Henrique Gomes da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 09/53850-6 - Acquisition of a mass spectrometer forin-depth studies of the mechanisms of degradation of organic compounds in reactors applied to wastewater treatment and to the production of bioactive commercial compounds
• Grantee: Marcelo Zaiat
• Support Opportunities: Multi-user Equipment Program