Development of a novel semi-empirical kinetic model applied to photocatalysis under UVC and solar radiation

Abstract

In this work, the degradation of the fast green dye FCF (FG) by means of photocatalysis under natural solar and UVC radiation was studied. The following degradation parameters were evaluated: catalyst type, catalyst dosage, initial dye concentration and pH. Phytotoxicity evaluation was also carried out using Lactuca sativa seeds. ZnO promoted better degradation rates in both radiations, under the best experimental conditions (0.06 g of catalyst, 10 mg L⁻¹ of FG and pH = 6). A generalist kinetic model was developed in order to allow its broad use in a wide range of photodegradation systems. The developed kinetic model was able to fit to the total set of generated data with a coefficient of determination R² = 0.95. The phytotoxicity tests showed an increase in the relative growth of the roots after treatment, indicating a reduction in toxicity of the solution and the efficiency of the process.