Determinación de la degradación del agua residual de los laboratorios ambientales de la Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología tratada mediante fotocatálisis (TiO2/UV)

Abstract

The wastewater generated by the environmental analysis laboratories of educational institutions may present contaminating compounds that need to be treated. In this project, the advanced oxidation process was investigated using titanium dioxide in suspension irradiated with UVC light, to degrade organic contaminants present in wastewater from chemical determinations of the environmental analysis laboratory of the Faculty of Food Sciences and Engineering of the Technical University of Ambato. The variation of the pH of the solution, hydrogen peroxide concentration, reaction time and level of contamination of the sample was studied. The effectiveness of the treatment was evaluated by COD removal efficiency. The best treatment presented a COD elimination percentage of 50,33 percent at a pH of 5,6, at a concentration of 70 milligrams per liter of hydrogen peroxide and 120 minutes of exposure, in the sample pretreated by neutralization and diluted to an organic loading concentration of 300 mg COD per liter. A high removal of other contaminants was observed, such as iron, zinc, manganese and heavy metals; Additionally, a high removal of sulfates, phosphates and nitrates was achieved. The BOD5 to COD ratio of the effluent pretreated by neutralization was 0,40, while this ratio was 0,11 for the wastewater treated by photocatalysis, which indicates that after the photocatalytic treatment, oxidation byproducts that are less biodegradable than the organic components of the pretreated effluent.