Remoção de matéria orgânica de efluente secundário em wetland construído utilizando macrófita do cerrado e resíduo da construção civil

Abstract

In the present work, the organic matter removal efficiency of two pilot-scale synthetic secondary effluent treatment units was evaluated, the U-Plant unit, a constructed vertical flow wetland (WC-FV) with Cerrado macrophyte (Eleocharis acutangula), and U-Filter a vertical flow filter (FVV) without plant. The filter bed structure of the two units was composed of medium/coarse sand and ceramic construction waste (CCCR), arranged in gravel 0 and 1 granulometry. The feeding of the systems was by batches, with hydraulic detention time (HDT) of 7 days, and varying organic matter applied, in phase 1 with 70mg/L and in phase 2 with 300mg/L, measured in terms of Chemical Oxygen Demand (COD). In addition to the measurement of COD, the parameters pH, conductivity, total dissolved solids (TDS), and turbidity were monitored at the inlet and outlet of the units. The results of turbidity removal reached values higher than 90% and, in relation to pH, it was stabilized by the systems between the values of 5 to 9, which are in accordance with CONAMA 430/2011. The efficiencies of organic matter removal in the units did not obtain significant values in phase 1, were negative data that represent that the output COD was higher than the input, by the incipient microbial community in the biochemical processing of MO. In phase 2, the removal results for total COD in U-Plant were 53% and in U-Filter was 62% and for filtered COD, in U-Plant was 70% and in U-Filter was 68%. Also, there was no statistical difference between the removal efficiencies of MO from U-Plant and U-Filter, noting that the presence of the plant does not affect the removal.