Estudo da degradação dos antibióticos beta-lactâmicos amoxicilina e ampicilina e avaliação da toxicidade e biodegradabilidade dos seus produtos / Degradation of the pharmaceuticals amoxicillin and ampicillin and evaluation of toxicity and biodegradability of derived-products.




The presence of active pharmaceutical substances and personal-care products in aquatic environment has been a great concern for the scientific community. Pharmaceutical industries are one of the main sources of these types of compounds, which are characterized by low degradability and high toxicity. The antibiotic preparation may negatively affect living organisms in water bodies. However, some organisms in the water bodies may become resistant after their contact with the bioactive chemical wastes. In the present work the efficiency of some homogeneous Advanced Oxidation Process (AOP) UV, H2O2/UV, Fe2+/H2O2, Fe2+ H2O2/UV, Fe3+/ H2O2, Fe3+/ H2O2/UV e Fe2+/ H2O2/solar radiation was investigated toward the degradation of AMX and AMP. The effect of relevant experimental parameters Fe+2, Fe+3, H2O2 concentration and the UV radiation was investigate. The Fenton process (Fe2+/H2O2) offered the most promising results, mainly accounts of high degradation capacity higher than 97% at reaction time 60 min. This process is high operational, simplicity and low coast. The efficiency of Fenton process was available using UV-Vis spectral data and chemical oxygen demand (COD). The results showed that AOP Fenton and AOP photo-Fenton are able to reduce near 100% of the concentrations of AMX and AMP after 60 min of reaction. The reduction of COD using Fenton process reached 75% and 81% for AMX and AMP, respectively. Solid residues from AMX and AMP oxidation reactions produced by Fenton reagent was evaluated by infrared spectroscopy (IR). The IR results showed the presence of carbonic compounds for both antibiotics. Toxicity tests with Artemia salina and Allium cepa were performed because of fast answers related to the toxicity of by-products from oxidation process. Artemia salina was efficient for the AMX/Fenton and AMP/Fenton, which showed DL50= 70% (v/v), after 48 h, and DL50= 50% (v/v), after 72 h, respectively. Allium cepa was efficient for chemical solution greater than 5% dilution (v/v) for both AMX and AMP considering the effects of toxicity on roots growth. Allium cepa showed changes in the mitotic cellular cycle for both AMX and AMP under Fenton reagent. It indicates an eventual mutation in the cellular genetic content. The biodegradability (BOD/COD) of Fenton process residue was investigated and shows the low biodegradation for AMX residues.


degradação de antibióticos compostos farmacêuticos biodegradabilidade quimica

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