Aeração e consumo energético em biorreatores com membranas (MBR): Revisão de literatura e estudo de caso

Abstract

In wastewater treatment, membrane bioreactor system (MBR) usually has a higher operational cost than the conventional activated sludge system (CAS), mainly due to the energy costs related to the aeration. This work reviewed the literature in the MBR system, seeking to identify the aeration fundamentals both in the biological process and in the use of air for membrane scouring to mitigate incrustation on membrane surface, its impacts on energy consumption, strategies to reduce this consumption, as well as evaluated its applicability in an industrial scale case study, in which the MBR system is used as a step in an effluent treatment system of a dairy factory. The result of the literature review presented several strategies aimed at reducing energy consumption and the case study confirmed: the good performance of this technology, with the following organic matter removal efficiencies achieved - BOD, 98,6 to 99,5%, COD, 96,1 to 99,2% and the high percentage of energy consumed by aeration in the MBR (around 85%). This fact renders evident that the reduction of energy consumption always must been seen with special attention, in order to increase the competitiveness of this technology.