Long-Term Anaerobic Structured Fixed-Bed Reactor Operation for Domestic Sewage Treatment: Performance and Metal Dynamics
Julliana Alves da Silva,
Adriana F. M. Braga,
Larissa Quartaroli,
Fernando G. Fermoso,
Marcelo Zaiat,
Gustavo H. R. da Silva
Affiliations
Julliana Alves da Silva
Department of Civil and Environmental Engineering, São Paulo State University (UNESP), Av. Engenheiro Luiz Edmundo Carrijo Coube, 14-01, Vargem Limpa, Bauru 17033-360, SP, Brazil
Adriana F. M. Braga
Biological Processes Laboratory, Center for Research, Development and Innovation in Environmental Engineering, São Carlos School of Engineering (EESC), University of São Paulo (USP), Engenharia AmbientalBloco 4-F, Av. João Dagnone, 1100-Santa Angelina, São Carlos 13563-120, SP, Brazil
Larissa Quartaroli
Department of Civil and Environmental Engineering, São Paulo State University (UNESP), Av. Engenheiro Luiz Edmundo Carrijo Coube, 14-01, Vargem Limpa, Bauru 17033-360, SP, Brazil
Fernando G. Fermoso
Instituto de la Grasa (C.S.I.C.), Campus Universitario Pablo de Olavide, Edificio 46, Ctra. de Utrera, km. 1, 41013 Sevilla, Spain
Marcelo Zaiat
Biological Processes Laboratory, Center for Research, Development and Innovation in Environmental Engineering, São Carlos School of Engineering (EESC), University of São Paulo (USP), Engenharia AmbientalBloco 4-F, Av. João Dagnone, 1100-Santa Angelina, São Carlos 13563-120, SP, Brazil
Gustavo H. R. da Silva
Biological Processes Laboratory, Center for Research, Development and Innovation in Environmental Engineering, São Carlos School of Engineering (EESC), University of São Paulo (USP), Engenharia AmbientalBloco 4-F, Av. João Dagnone, 1100-Santa Angelina, São Carlos 13563-120, SP, Brazil
To achieve optimal performance, anaerobic digestion (AD) requires well-balanced operation conditions, steady physical–chemical conditions, and adequate nutrient concentrations. The use of anaerobic structured-bed reactor (ASTBR) presents these conditions. However, several additional investigations are required to elucidate robustness to treat domestic sewage (DS). This pioneering study investigated the performance of an ASTBR in treating DS across four decreasing hydraulic retention times (HRTs) (12, 8, 6, and 5 h). The study aimed to assess organic matter removal, the influence on physical–chemical parameters, and the monitoring of trace metals (TMs) during long-term operation (614 days). Overall, the results underscore the viability of employing ASTBR for DS treatment, achieving an average chemical oxygen demand (COD) removal efficiency of 70%. The system demonstrated consistent long-term operation over 614 days, maintaining stability even with decreasing hydraulic retention times (HRTs). The average effluent concentration of volatile fatty acids (VFAs) was 20.4 ± 3.3 mg L−1, with a pH value averaging 7.2 ± 0.1. TM concentrations at an HRT of 12 h exhibited higher levels in the effluent compared to the influent, gradually decreasing over the course of operation and ultimately stabilizing at levels similar to those observed in the influent. The concentrations of metals, including Ba, Cr, Fe, Mn, Ni, Pb, Se, and Zn, monitored in the effluent samples adhered to the allowable discharge thresholds as stipulated by Brazilian regulations.
