Treatment of liquid waste produced in a small chemical laboratory using the photo-fenton process

Abstract

The photo-Fenton process, an advanced oxidative process (AOP), is a promising method for the treatment of liquid effluents. The aim of this work was to investigate the photo-Fenton process for the treatment of a liquid waste produced in a chemical laboratory at the Technology Faculty (State University of Amazonas, UEA). The effluent was initially characterised for its colour, COD, total phenols and UV/VIS absorptivity. Later, the influence of Fe2+ and H2O2 was investigated for the reduction of colour and total phenol through a 22 factorial experiment arranged in a star. The characterised liquid residue presented high values for colour (2462.1 UC), phenols (90.96 mg/L) and Chemical Oxygen Demand (977.7 mg O2/L) and, thus is potentially dangerous for the environment. The considered statistical models were in good agreement with the experimental results. The best theoretical conditions were 0.75 g/L of Fe+2 and 16.03 g/L of H2O2 for colour reduction (99.6%) and 0.59 g/L of Fe+2 and 29.4 g/L of H2O2 for total phenol reduction (81.2%).