Decentralized treatment of hospital wastewater in two-phase anaerobic bioreactors: evaluation of antibiotic removal

Abstract

The increasing use of antimicrobial drugs in recent years and the growing emergence of microorganisms with antibiotic resistant genes has aroused interest of the scientific community for several public health problems and environmental impacts. Among the problems, there is the inefficiency or increase in the dosage of antibiotic drugs for medical treatments and, being only partially metabolized by the body, are excreted in the urine. Although the sanitary sewage treatment systems currently applied show organic matter removal rates greater than 80%, the removal efficiency of organic micropollutants (OMPs), including antibiotics, in conventional treatment systems remains a challenge. Another aggravating factor regarding the contribution of antibiotics to the environment is the discharge of hospital effluents into sewage collection systems, joining domestic effluents, without any type of prior treatment, which can make the removal of emerging micropollutants even more challenging. Thus, the aim of this research project is to evaluate the potential of the decentralized anaerobic treatment system for the removal of antibiotics from hospital effluents, using two-phase bioreactors (acidogenic and methanogenic). Five fluoroquinolones antibiotics, six sulfonamides and one trimethoprim will be evaluated. In addition to monitoring the OMPs and their metabolites and products through physicochemical analyses, molecular biology analyzes will be carried out at different stages of the process, in order to identify the microorganisms involved and try to elucidate some gaps related to microbial metabolism and the biodegradation of these antibiotics.