Avaliação da degradação de microcistina – LR no tratamento de água de abastecimento em sistema convencional seguido por Processo Oxidativo Avançado (POA)

Abstract

Among the deleterious effects caused by the process of eutrophication of natural waters, an important highlight should be the appearance of cyanobacterial blooms and the consequent generation of cyanotoxins with a potent hepatotoxic effect (eg microcystin- LR). In general, conventional treatments for water purification are inefficient for the removal of these micropollutants, which has stimulated the study of new treatment alternatives. The advanced oxidative processes have been an interesting alternative because of their potential as alternatives or complements to conventional processes of water treatment, since the hydroxyl radicals generated are highly reactive and not selective, and can act in the chemical oxidation of a wide range Of substances. These processes generally involve the generation of highly oxidizing and non-selective species, such as the hydroxyl radical (• OH) and, in some cases, oxygen, thus being efficient in the removal of various contaminants. The main objective of this work was to verify the potential of two advanced oxidative processes: UV/H2O2 and Fenton in relation to the treatment of water destined for public supply contaminated by microcystin-LR. For this, the research was divided into three stages. In the first stage, the validation of the analytical method was carried out using high-performance liquid chromatography coupled to massspectrometry (HPLC-MS) for identification and quantification of the toxin described in Chapter 1. Chapter 2 describes the efficiency of conventional treatment Followed by the advanced oxidative process (UV/H2O2) in relation to the treatment of water intended for public supply with emphasis on the efficiency of a low cost photocatalytic reactor for microcystin-LR degradation. Then, the third and final chapter presents the use of Fenton reagent as coagulant, followed by flocculation, sedimentation and filtration, with the purpose of removing turbidity, apparent and true color and microcystin-LR also presente in public water supply.