Evaluation of the effect of hydraulic retention time on the biodegradation of organic micropollutants in a structured fixed-bed aerobic reactor treating domestic sewage

• Grant number: 24/21994-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: December 31, 2025
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Rodrigo Braz Carneiro
• Grantee: Maria Fernanda Nogueira
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 22/10615-1 - Consolidation of the biorefinery concept applied to the biological treatment of wastewater and solid wastes, AP.TEM

Abstract

The presence of organic micropollutants (OMPs) in aquatic environments has become an increasingly relevant environmental issue worldwide in recent decades. Although present in trace concentrations, micropollutants can cause harm to both human and environmental health, being associated with the development of various types of cancer, infertility and bacterial resistance. Most studies involving the evaluation of OMP removal in conventional treatment systems focus on the use of activated sludge systems as a biological treatment phase, which involves the suspended growth of biomass. However, in most cases, OMPs are not effectively removed in conventional treatment systems. Research has shown that the use of reactors based on biomass immobilization on support materials can achieve greater hardiness in terms of applied organic load and, consequently, lower hydraulic retention times compared to systems based on suspended growth. In this context, the present research project proposes to evaluate the specific effect of the hydraulic retention time (HRT) on the aerobic biotransformation/degradation of certain OMPs in an aerobic fixed-bed reactor with polyurethane foam, treating domestic sewage. The target OMPs selected in this research are commonly found in domestic wastewater, effluents, and sludge from wastewater treatment plants, namely: ibuprofen, diclofenac, atenolol, propranolol, carbamazepine, sulfamethoxazole, sulfadimethoxine, trimethoprim, ciprofloxacin, and ofloxacin. The project aims, therefore, to elucidate whether adjusting the HRT in reactor operation can improve the biodegradability of OMPs without compromising the performance of sewage treatment.