EVALUATION OF DIURON REMOVAL IN WATER WITH USE OF COMPLEMENTARY TECHNOLOGIES ASSOCIATED WITH COMPLETE CYCLE TREATMENT

Abstract

In this work were proposed two complementary alternatives to be associated to the complete cycle for diuron removal, present in surface waters: advanced oxidative process, with hydrogen peroxide and ultraviolet radiation, and adsorption in granular activated carbon. The study water solution was prepared with characteristics similar to Pardo River. It was observed that the water treatment technology in complete cycle, after jartest trials, presented an average removal of 27% of the herbicide. The filtered water was submitted to the oxidative process, through different initial concentrations of hydrogen peroxide and residence times, through the variation of the volumetric flow of the liquid stream affluent in tubular reactor, operated in continuous flow. Diuron removal was increasing at the time and dose of applied radiation, resulting in 99.9% degradation. However, the total organic carbon analysis showed maximum removal of 54%, which indicates the formation of smaller organic unwanted compounds after the degradation of the initial molecule. The adsorption tests in granular activated carbon were performed using the methodology of rapid tests on a small scale to obtain the experimental rupture curve. The maximum herbicide concentration allowed by potability standards was adopted as a breaking point. From the methodology of rapid tests in reduced scale, was obtained the operation time for adsorption column in real scale of approximately 6 months. Thus, complementary technologies, in association with full-cycle surface water treatment, reproduced satisfactory results regarding diuron removal.