Cattle Farm Wastewater Treatment by Vertical Flow Constructed Wetland System

The present work evaluated a vertical flow constructed wetland (CW) system for the treatment of cattle farm wastewater. Was constructed 5 treatment systems in drums of approximately 50 L, 4 filled with plant (vetiver grass) and one without plant, with the base for the 5 units filled with gravel and sand. In a period of 3 days, samples were collected every 24 h before and after treatment. Values of evapotranspiration obtained for CW's was between 11.1 to 73.0% and the rate of surface application ranging from 0.07 to 0.13 m3m-2d-1. The CW without a plant showed evapotranspiration between 32.7 to 82.3% and with a surface application rate between 0.09 and 0.14 m3m-2d-1. The sand presented a CU of 5.3 with a d10 of 0.265 mm and d60 of 1.088 mm. The gravel presented a uniformity coefficient of 5.3; d10 and d60 of 2.771 and 14.785 mm, respectively. In general, in WC's systems with the presence of vetiver grass, the most expressive results were observed in relation to WC without plant. The samples collected during the study showed high pollutant removal rate, obtaining average removals of 95.3% for COD, 94.2% for P-PO43-, 98.0% for N-NH4+ and 93.1% for N-NO3-.