Assessment of the first-order kinetic removal models on constructed wetland in a Mediterranean area

The objective of the study was to compare the main kinetic models used to identify pollutants degradation in horizontal subsurface-flow constructed wetlands (HSSF-CWs) and assess the areal removal rate constant (k, m year-1) of the systems operating in Mediterranean regions. The ideal plugflow model reactor, the continuous flow stirred tank reactor (CSTR) model and the P-k-C* model were applied in two HSSF-CWs systems in Sicily, one located in San Michele di Ganzaria (SMG) and the other used to treat wastewater (WW) from IKEA store in Catania. Using P-k-C* model, the COD k values measured in SMG and IKEA (58.54 m y-1 and 50.13 m y-1 respectively) were of the same order of magnitude, as well as, the Nitrate k values (47.33 m y-1SMG and 53.29 m y-1 IKEA). Data processed with a CSTR model (N=1 value) gave significant differences. The values of k20 and θ obtained using the P-k-C* model, which better represents the measured pollutant degradation, were 52.07 m y-1 and 0.9986 for COD and 49.48 m y-1 and 0.9920 for NO3-. The data analysis by period indicates similar values of k for both pollutants at SMG and IKEA, with a higher k values in the period October-March.