INTERFERÊNCIAS PLUVIOMÉTRICA E TEMPORAL NA HIDRODINÂMICA DE WETLAND CONSTRUÍDO DE FLUXO SUBSUPERFICIAL VERTICAL NO TRATAMENTO DE ESGOTO DOMÉSTICO

Abstract

The aiming of this research is to evaluating the pluviometric and temporal interferences in a vertical subsurface flow constructed wetland system (CW-FVS) used for the treatment of domestic wastewater in full scale. The values obtained in three tests using as tracemaker the sodium chloride (NaCl), were compared. Two of them without rainfall: one in the year 2018 (NR-2018) and another in the year 2020 (NR-2020), and a last test carried out with the presence of rainfall in the order of 50 mm (R-2020). The monitoring of electrical conductivity enabled the elaboration of residence time distribution (RTD) in all tests, being able to understand the hydrodynamics of the system. Were observed significant variations between all scenarios with regard to hydraulic retention time (HRT), dispersion number (d) and serial tank model - TIS (N) variables. There were no significant differences in the parameters of volumetric efficiency (Ve) and in the short-circuit index (SCI) in all scenarios. An increase in the presence of clooging was also observed in the two years of system operation, which is well designed, even considering the variables of the water balance (evapotranspiration and precipitation). Although there was a slight change in the sewage flow, in all scenarios the trend towards the complete mixture model (CSTR) prevailed.