Degradação de antibióticos de uso veterinário em reator de carbonização hidrotermal

• Autor(a) principal: Santos Júnior, Laurivê Antônio dos
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/5174
• topic: Antibióticos veterinários; Decomposição; Carbonização hidrotermal; Veterinary antibiotics; Decomposition; Hydrothermal carbonization; ENGENHARIA SANITARIA::RECURSOS HIDRICOS

Antibiotics are widely used in human and veterinary medicine. After consumption, much of the drug is excreted unchanged or in the form of metabolites, and through the release of sewage treatment plants, agricultural waste and leaching, reach natural ecosystems. The occurrence of antibiotics in aquatic environments has become a growing concern worldwide mainly due to the emergence of resistance genes in pathogenic bacteria. The indiscriminate use and the use of subtherapeutic doses of antibiotics cause the emergence of resistance. In Goiás, a recent survey showed the presence of bacteria resistant to multiple antibiotics in hospital wastewater and Goiania sewage treatment plant. The wastewater treatment processes based on biological degradation have low efficiency of removal of residual drugs due to recalcitrant structure and biocide effect of antibiotics. The objective of this research was to evaluate the efficiency of hydrothermal decomposition of the antibiotic ampicillin, enrofloxacin, oxytetracycline, and tylosin sulphaquinoxaline. For this purpose, the antibiotic solutions were prepared at a concentration of 50 μg.mL-1 and pH correction to the range 3-7, with phosphoric acid solution for the hydrothermal carbonization treatment. Treatment by the hydrothermal carbonization process of oxytetracycline with pH adjustment made with phosphoric acid, pH 3, 170 ° C temperature and 90 minutes reaction time showed total decomposition as a result of this antibiotic (100%). The highest decomposition rate (98.37%) for enrofloxacin was observed when they were used the reaction time of 120 minutes, pH 3, 200 ° C temperature and phosphoric acid as a catalyst. The highest decomposition rate of ampicillin (94.86%) was observed when using time of 120 minutes reaction, pH 4, 200 ° C temperature and phosphoric acid as a catalyst. The most suitable conditions for the decomposition of sulphaquinoxaline, observing the greatest reduction rate (95.71%) was observed when they were used the reaction time of 120 minutes, pH 5, temperature 180 ° C and phosphoric acid as a catalyst. All conditions, except for the pH 7, led to complete decomposition of tylosin (100%) of the samples. The best condition for the decomposition of tylosin, observing a lower energy expenditure, and reaction time spent catalyst was one which was used 90 minutes reaction time, pH 4, 180 ° C temperature and phosphoric acid as a catalyst. In the germination test with Allium cepa, the solutions treated, except ampicillin, had similar germination rates found in the control group. The solutions of antibiotics with no treatment showed higher rates of growth of buds when compared to the control group. These results show that the hydrothermal carbonization process has potential for future applications decomposition of antibiotics in contaminated water and effluent.