Neste artigo, avaliou-se a eficiência de quatro sistemas alagados construídos (SACs) no tratamento de esgoto sanitário após ser submetido a tratamento preliminar e, no caso de alguns SACs, a tratamento primário (tanque séptico). Os SACs foram cultivados com lírio-amarelo (Hemerocallis flava), tendo a brita #0 como meio suporte, e submetidos às taxas de carregamento orgânico (TCO) de esgoto sanitário, em termos de DBO (kg ha-1 d-1), de 44; 98; 230 e 395 kg ha-1 d-1 e tempos de detenção hidráulica (TDH) de 3,9; 2,0; 1,0 e 0,75 dias, respectivamente. Para avaliar a eficiência dos sistemas, foram realizadas, no afluente e no efluente aos SACs, análises de DBO, DQO, SST, N-total, P-total, K e Na durante 6 meses de funcionamento do sistema. Nos SACs, houve predominância do ambiente anóxico/aeróbio, com remoção de SST, DBO e DQO, suficiente para atender aos padrões de lançamento de efluentes estabelecidos na legislação ambiental do Estado de Minas Gerais.

In this paper, it was evaluated the efficiency of four constructed wetlands (CWs) in the treatment of sewage after being subjected to preliminary treatment, and for some SACs, primary treatment (septic tank). In CWs planted with yellow lily (Hemerocallis flava), since the gravel #0 as the support medium, and submitted to organic loading rates (OLR) of sewage, in terms of BOD (kg ha-1 d-1): 44, 98, 230 and 395 kg ha-1 d-1 and hydraulic detention times (HDT) of 3.9, 2.0, 1.0 and 0.75 days, respectively. To evaluate the efficiency of systems, analysis of BOD, COD, TSS, total-N, total-P, K and Na were performed in the influent and effluent to the SACs for 6 months of operation of the system. In all the CWs there was predominance of the anoxic/aerobic environment, and high efficiencies in the removal of TSS, BOD and COD were obtained, meeting the effluent discharge standards set by the environmental legislation of the Minas Gerais State.