Dimensionamento de um sistema de wetlands construído de fluxo vertical para pós-tratamento de efluente de cervejaria

Abstract

Constructed Wetlands are an innovative and promising technology for the treatment and aftertreatment of industrial effluents, due to their easy operation and very low maintenance periodicity. The present work presents the dimensioning project of a Vertical Flow Constructed Wetlands system planted with Heliconia Rostrata, for posttreatment of industrial effluent from a brewery. A database was used on the brewery effluent containing: average flow, Chemical Oxygen Demand, Biochemical oxygen demand and Total Nitrogen Kjeldahl to define the design criteria. The design criteria used were: Surface Application Rate, Organic Limit Load and Mass Balance for Dissolved Oxygen. The final project resulted in a surface area of 5.00.00 m² and calculation memorial with dimensioning of reservoir, dimensioning of the feeding and pumping system and drainage system. The filtering substrate of the system is composed of sand (0.25 mm < D10 < 0.40 mm) in the most superficial layer, gravel nº0 (3.00 < D10 < 10.00 mm) for the intermediate layer and gravel nº2 (20 , 00 mm < D10 < 40.00 mm) for the deepest layer. Operation and maintenance criteria have been suggested to achieve a theoretical efficiency of 80% MO removal and 56.4% average removal of Total Nitrogen. Finally, it was concluded that the designed system, if properly executed, can meet the specificities of the effluent release standards of the current legislation in Brazil and the State of Parana.