Pós-tratamento de efluente de reator UASB por sistemas alagados construídos de fluxo vertical

Abstract

The objective of this work was to evaluate the behaviour (efficiency) of Constructed Wetlands (CW) as post-treatment of anaerobic effluent from upflow anaerobic sludge blanket reactor (UASB) treating sanitary sewage from Universidade Tecnológica Federal do Paraná, campus Campo Mourão. Two constructed wetlands were set up in bench scale (47,55 L each), one of them being planted with seedlings of aquatic macrophyte Eleocharis mutate (L.) Roem. & Schult., native from the region (CW1); and another with sand and grit #1 (without seedlings of aquatic macrophyte (CW2), as a control unit. Both systems were operated in batches of 48 h and 12 h from May to December of 2012. Physical-chemical parameters were determinate: liquid temperature, pH, organic matter concentration (COD), ammonia nitrogen, nitrite, nitrate, phosphorus and total solids according to Eaton et al. (2005) methodologies. All the assays were carried out in duplicate, being made 3 assays for 48 h and 2 assays for 12 h. Results of COD and ammonia nitrogen were adjusted from kinetic models of 1st and 2nd order to obtain the apparent kinetic constants. Kinetic model of 1st order adjusted better the experimental results of raw and filtered COD in the batch assays of 48 h and 12 h and 2nd order to ammonia nitrogen. This technology was efficient to the post-treatment of anaerobic effluent once Eleocharis mutata (L.) Roem. & Schult specie contributed in the removal of raw and filtered COD, TNK, ammonia nitrogen and phosphorus with values higher than 45% in the vertical flow.