Remediação de efluente sintético de matadouro usando uma combinação de Digestão biológica anaeróbica e processos de Fotoeletrofenton solar

Anaerobic Digestion (AD) process exhibit an energetic attraction due to the production of methane during the degradation of organic matter [1]. However, this type of treatment does not remove the bio-resistant organic compounds present in the wastewater. The electrochemical advanced oxidation processes are an excellent alternative for the elimination of persistent contaminants in the wastewater, being the process of Solar Photo Electro-Fenton (SPEF), which presents a high efficiency in the removal of these type of pollutants [2]. In this work, the behavior of the UASB reactor with two different initial charges of synthetic wastewater (1700 (A) and 3500 (B) mg COD/L each one) was studied. The reactor was fed continuously with 2.5 L of synthetic slaughterhouse wastewater during 30 days and with a 10 h hydraulic retention time (HRT). In each case, the removal of chemical oxygen demand (COD) was 90% for A and 60% for B after 15 days. After UASB reactor, the wastewater was conducted to a pilot plant contained an electrochemical filter press cell with a DSA anode and an Air-difussion cathode coupled to solar photoreactor. The removal of bio-resistant substances by SPEF was studied. 5 L of solutions containing 280 and 1000 mg L-1 of COD organic matter with 0.5 mM of Fe2+ and 0.05 M Na2SO4 at pH 2.8, applying a current density of 25 and 10 mA cm-2 were treated. A complete mineralization of organic matter was obtained by SPEF process at the end of electrolysis, showing the application of combination processes to the treatment of slaughterhouse wastewater.