Aplicação do processo eletro-fenton na remoção de uma solução de ciprofloxacina (CIP) utilizando eletrodo de ferro fundido

Abstract

The following research aimed to evaluate the application of electro-Fenton (EF) process on the removal of Ciprofloxacin in aqueous solutions. A batch reactor on a laboratory-scale was developed, consisting on a borosilicate bequer composed of 4 molten iron plates, with effective area between plates of 152,22 cm 2 . The experiments were conducted with an initial solution pH of 5,6 and the investigated variables were: current intensity (I) (A), [H 2 O 2 ] (mg L - 1 ), rate of O 2 dissolved (L min -1 ). At electrolysis time of 0 to 90 min, aliquots were removed from the samples for immediate analysis of CIP concentration, residual H 2 O 2 , solution pH and total dissolved iron (TDI). Applying a response surface methodology (RSM) it was possible to evaluate the best experimental conditions of the process: I (0,4 – 0,8 A), [H 2 O 2 ] (> 400 mg L -1 ) at electrolysis time of 3 min, acquiring a removal superior of 83% of the CIP. Suggestion is that parallel reactions and/or simultaneous electrocoagulation and electro-oxidation may be occurring at the EF reactor. This fact may be associated with the presence of iron ions dissolved on the solution at conditions of pH ~ 7 and immediate consume of the initial concentration of H 2 O 2, favoring nevertheless reactions via electrocoagulation. However, the principles of EF process dictate that at the presence of H 2 O 2, iron ions and dissolved O 2 injection at reactive environment occurs a hydroxyl radical (•OH) generation, concluding on oxidation reactions (degradation and/or mineralization) of CIP. The EF process was efficient on the CIP removal, enabling the declination of environment impacts and prevention regarding to the alterations and/or mutations on the aquatic fauna and flora, as well as on the human health.