Design of a photocatalytic reactor (uv-a) for the study of the chemical degradation of 1,2- dihydroxybenzene and inactivation of e. coli in simulated water

Abstract

For water disinfection, conventional methods have been applied with some drawbacks towards the formation of potentially dangerous disinfection products. Advanced oxidation processes such as photocatalysis are less expensive, using fluorescent ultraviolet light lamps. The intense oxidation and mineralization reactions of contaminants can be increased in the presence of molecular oxygen or H2O2, resulting in a highly efficient process due to the formation of reactive oxygen species, which leads to an efficient degradation of contaminants in an aqueous medium to form compounds or residues. with low toxicity. The photocatalytic remediation of 1,2-dihydroxybenzene and the inactivation of E. coli in simulated waters was carried out after the construction of a photocatalytic reactor with a 10W UV light source at 365 nm based on the LED light emitting diode - UV energetically. efficient due to direct light incidence and the reduction of electron-hole recombination that increases photonic efficiency. To carry out the degradation process of 1,2-dihydroxybenzene, a three-level 3k factorial design was applied for the catalyst concentration (TiO2), pH level and H2O2 concentration, showing favorable results for acid pH and low amount of catalyst. . To evaluate the inactivation of E. coli, the bacterial growth curve of the ATCC 25922 strain was studied in Nutrient culture medium, using the UV-vis technique. Spectral scanning was performed from 200 to 800nm, obtaining the maximum absorption at 300nm and an exponential growth phase of 4 to 5 hours at 37°C and pH 7.0.