This work presented the results of a 19-month study on the performance of constructed wetlands in terms of organic matter, solids, nutrients and coliforms removal in pilot scale unities with horizontal, subsurface and surface flow, with hydraulic retention time from 1.3 to 5.3 days, as post-treatment of UASB effluents (domestic wastewater). Organic matter and solids were effectively and consistently removed, with average values of 70, 80 and 60% for TSS, BOD5 and COD, respectively. Nutrients removal, after a promising start up, became unstable and apparently influenced by temperature. The treatment system has also shown high potential to remove coliforms, although with relatively wide variations over the study period: ≈ 2 log10 reduction of total coliforms and 2-4 log10 reduction of Escherichia coli.
Brachiaria arrecta; horizontal flow; Typha sp; constructed wetlands
