BIORREATOR A MEMBRANA APLICADO AO TRATAMENTO DE EFLUENTE DA INDÚSTRIA DE LATICÍNIOS: AVALIAÇÃO DA INSERÇÃO DE MATERIAL SUPORTE NO DESEMPENHO E NA COLMATAÇÃO DA MEMBRANA

Abstract

Membrane bioreactor allows the combination of a biological degradation incorporated to a membrane filtration in a single chamber reactor, resulting in an excellent quality treated effluent that can have even a better quality when a support compost is added to the system, favoring the microorganism growing in the reactor. The main objective of this study was the evaluation of a miscellaneous movable layer insertion in a membrane bioreactor used in a dairy industry, aiming the removal of differrents polluents and the minimization of the membrane bridging compared to a conventional one. In a preliminary test the membrane aeration rate and critical flow were obtained, and the results were, respectively, 3 m³.m-².h-1 e 7,2 L.m-2.h-1. Then, the study was splitted in two differents phases, in the first one, the conventional reactor runned during sixty days for a comparing parameter, the second phase the effects of the support material in the system was evaluated as so the biofilm growing in both of the two materials types for the same period of time. When the results obtained in both phases, it was perceived a significant improvement of the membrane bioreactor for the chemical oxygen demand, phenols, Kjeldahl total nitrogen, ammoniacal nitrogen and true color removal. Other factor that was influenced by adding a movable layer was the specific autotrophic growing rate which have had a growth of the microorganisms presence that are responsable for the nitrogenous compounds removal in the support material. Regarding the membrane bridging, it was posible to notice an expressive reduction of the transmembrane pressure in the presence of the support material, resulted from a better system turbulence and homogenization and the shear caused by the movable layer on the membrane surfaces, that continously romoves adhered particles. Evaluating the microbiological growing in both support materials it was noticed a substantial difference in the volatile suspended solids content where it was favored the biofilm growing when the higher diameter support material and surface area were used, Therefore, it can be concluded that the using of a movable layer is a high potential alternative for an improvent in the dairy industry membrane bioreactor treated wastewater.