Up to 95 % reduction of chemical oxygen demand of slaughterhouse effluents using Fenton and photo-Fenton oxidation

Abstract

Meat industries produce effluents containing high concentrations of organic and inorganic compounds, which must be removed before being discharged or reused. Advanced oxidation processes using Fenton reaction coupled with UV, solar radiation, and electrochemical oxidation are promising methods. Here, we treated the effluent from an anaerobic digester using: (a) the photoelectro-Fenton process, using a system with a Ti-RuO2 anode and a carbon felt cathode, (b) the solar photo-Fenton process, using a batch reactor and a compound parabolic collector, and (c) a combination of Fenton and solar photo-Fenton processes. The effluent had an initial chemical oxygen demand (COD) of 1159 mgL−1, and we obtained high removal efficiencies of COD, up to 95 %, using the combination of Fenton and solar photo-Fenton processes.