Estudo da eficiência dos processos Cl/UV e H_2 O_2/UV na degradação de bisfenol-A, 17 β estradiol e 17 α etinilestradiol: avaliação da atividade estrogênica e toxicidade

Abstract

Several substances are classified as endocrine disrupters, such as pesticides, active chemicals and those produced by natural and synthetic industries and estrogens. Chemicals interfere with the production, release, metabolism and production of hormones, and may mimic or block such action. Considering that these compounds may be present in several environmental matrices such as water, soil, sewage, sediments and leachate, studies to promote the elimination of these compounds have been growing more and more. Conventional treatments of water and sewage do not promote the complete elimination of these compounds, being necessary the development of new technologies, among them the advanced oxidative processes, that promote the removal of compounds through the generation of hydroxyl radicals. The objective of the study was to evaluate the degradation of the endocrine disrupters bisphenol A (BPA), 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2) by H2O2/UV and Cl / UV processes, investigating the aqueous matrix (ultrapure water, and tap water), UVA and UVC radiation, oxidant concentration and pH values at 5, 7 and 9. In addition to the removal of the compounds, the formation of the estrogen intermediates was investigated by the determination of the estrogenic activity of the samples before and after the treatment processes by the Yeast Estrogen Screen (Yeast Estrogen Screen), which uses the genetically modified Saccharomyces cerevisiae yeast. Chronic ecotoxicity tests with test organisms Ceriodaphnia dubbia and Raphidocelis subcapitata and physical-chemical parameters were also determined. H2O2/UV and Cl/UV processes presented different removal efficiencies of BPA, E2 and EE2 endocrine disrupters according to the experimental conditions adopted. The pre-treatment samples presented estrogenic activity with EQ-E2 value of 265 ± 6 μg.L-1, however after the treatments the estrogenic activity was removed to values below the limit of quantification after 5 and 20 minutes of reaction for Cl/UV and H2O2/UV, respectively. The toxicological tests demonstrated toxicity for the two test organisms and treatment processes analyzed.