Aplicação de um biorreator de membrana dinâmica para tratamento de águas residuárias

Abstract

The integration of membrane separation technology represents a major innovation in the evolution of biological treatment technology for effluents. The present work reports the performance of a dynamic membrane anaerobic bioreactor in the treatment of domestic wastewater, operated with the objective of removing eggs from helminths producing an effluent for agricultural reuse. An experimental system was constructed consisting of an anaerobic digester constructed from polyvinyl chloride (PVC) pipes and connections and a membrane module. The dynamic membrane module, in turn composed of a PVC structure and presents external configuration of circular shape, with total area of filtration with dimensions of 4x4cm. A polyethylene mesh (membrane support) with a mean porosity of 90μm and a metal mesh used near the membrane support are found inside to provide greater resistance to it when subjected to high pressure gradients inside the reactor, with filtration in perpendicular flow type. For that, the following operating parameters were performed: total COD, pH, alkalinity, turbidity, AGV, phosphorus, nitrogen and helminth eggs. We obtained concentrations of DQOt presented a removal of 84% resulting in a permeate with concentrations of 268mg / L at 89mg / L, for phosphorus and nitrogen, a removal of 88% and 83% was observed, resulting in concentrations of 5.23 varying at 1.21mg / L of total phosphorus and 36.18 varying to 21.2mg / L of NTK, respectively. Considering the results of pH, AGV and Total Alkalinity, it was observed that the reactor maintained in a pH range between 7.0 and 7.5 pH ranges found for crude and permeate sewage, respectively. The results of counting of helminth eggs observed that, except for the first sample of raw sewage analyzed, the others had counts of helminth eggs below 40 eggs / L, with an arithmetic mean of 21 eggs / L. In the effluent of the reactor, smaller counts were obtained, with a general average of 8 eggs / L, representing a removal efficiency in the reactor of the order of 61%. It was possible to verify that the use of the dynamic membrane provided a good performance for the filtration of the effluent, producing a permeate with promising characteristics, demonstrating that the use of this technology is a very interesting alternative for the removal of helminth eggs and possible reuse in the agricultural área.