Degradação da atrazina por processos oxidativos avançados na presença de ozônio

Abstract

The progressive increase in population demanded a greater demand for food, because of this agriculture became dependent on the use of pesticides to guarantee the development of crops on a large scale. Among the classes of pesticides, herbicides are the most used. Atrazine (ATZ) is a systemic and selective herbicide recommended for the control of weeds, due to its moderate mobility and high persistence has been identified as a polluting source of surface and groundwater. In this context, the importance of developing technologies and strategies for the degradation of these contaminants is observed, and an alternative to the degradation process is the advanced oxidative processes (POAs). These oxidative processes mostly use the combination with oxidizing agents such as ozone, which reacts with a wide class of organic compounds due to their high oxidation potential. In aqueous solution, the main parameters that affect ozone decomposition are temperature and pH. So that, with increasing temperature, ozone becomes less soluble and less stable, as far as the pH value is concerned, oxidation reactions can occur via direct (acidic) or indirect (basic) ozonation, or that is, in an acidic environment the level of dissolved ozone is higher than in an alkaline environment, since in this the decomposition in free radicals is favored. The objective of studying this work was to evaluate the efficiency of the POAs of the type: O3, O3/OH-, O3/Fe0 and O3/H2O2 on a laboratory scale, using a borosilicate glass reactor operating in continuous flow. The results obtained indicated that the process with the best efficiency was Peroxone (O3/H2O2), with the degradation of approximately 73% of atrazine being possible, suggesting a decrease in the potential for the treatment of water contaminated with atrazine.