Aplicação de biorreatores anaeróbios de membranas no tratamento biológico da água produzida do petróleo para produção de biogás

Abstract

The produced water, a significant byproduct of oil extraction, represents a major environmental challenge due to its complex composition and high pollution potential. This study investigated the application of anaerobic membrane bioreactors (AnMBRs) in treating this effluent, evaluating their efficiency in removing organic contaminants and producing biogas. AnMBRs combine anaerobic digestion with membrane filtration, standing out for their low energy consumption, reduced sludge production, and potential for resource recovery. Factors such as pH (maintained between 6.4 and 7.0), temperature (32-35 ºC), and organic load were monitored to optimize microbial performance and biogas production. The experiment was divided into four phases, starting with 100% domestic sewage, followed by 20% produced water mixed with 80% domestic sewage, then a 50% mix of each, and concluding with 100% produced water, allowing gradual adaptation of the AnMBR microbiota. The results demonstrated high system efficiency, with organic matter removal exceeding 81% for COD and BOD, and over 94% for TSS. Biogas production varied between 0.25 and 0.35 m³ CH₄/kg COD, with a range in methane composition from 35% to 74%. In addition to meeting standards, the process proved promising for mitigating environmental impacts in the oil industry and other industrial sectors, reinforcing its contribution to the sustainable management of resources.