This work aimed to obtain the adjustment of the mathematical model adapted from the first order kinetics and its respective parameters for describing the organic matter degradation in constructed wetlands (CWs) planted with yellow lily (Hemerocallis flava) for the treatment of domestic sewage. The CWs were cultivated with yellow lily and subjected to different surface organic loading rates (TCOs) of domestic sewage: 44, 98, 230 and 395 kg ha-1 day-1 BOD. The mathematical model adapted from the decay of organic material showed a good fit and adequately described the kinetics of removal of organic matter (COD) in the evaluated systems, with generally more than 75% R². In ascending order of TCO values of degradation coefficients (Kv) were, respectively, of 0.45, 0.69, 1.23 and 1.72 d-1, considered low for the first two CWs and normal for the other two, and the values of "n" of 0.448, 0.107, 0.327 and 0.461 in the range normally found in the literature.
constructed wetlands; ornamental plants; degradation kinetics
