Cinética de degradación y mineralización del colorante Rojo Amaranto por medio de la fotocatálisis con luz solar

Abstract

Introduction: Oxidation sensitized with TiO2 and sunlight, is a technique that can be used as a water purification system, especially on the treatment of liquid industrial wastes in which the content of synthetic toxic compounds are difficult to be eliminated by other conventional ways. Objective: To determine the kinetics of degradation and mineralization of the amaranth red dye contained in water during the photocatalysis process with titanium dioxide, using a parabolic cylinder sunlight collector. Materials and Methods: To determine the kinetics of degradation and mineralization of the amaranth red dye during photocatalysis, we proved the order of the reaction for each one of the experiments made, considering the color concentrations and residual COT in order to determine, afterwards, the constant rates of velocity and the mid-life times of the color contained in water after 8 hours of treatment. Results: Considering each of the conditions of the experiments, the most influential parameter on the times of the dye´s mid life is the use of TiO2, along with hydrogen peroxide. The shortest exposition to sunlight in which a 50% diminishing of the color was made (time of midlife) was 1.92 hours, for the condition in which 150mg/L of TiO2 and 2 ml/L of hydrogen peroxide were used. Under this condition a media rate of degradation of 93.48% was reached. Conclusion: The use of the adequate quantities and concentrations of TiO2 and H2O2 allows the treatment of dyed waters taking time periods lower than 8 hours of sunlight to degrade the color contained, in a high percentage, in water.