Combined treatment of vinasse by an upflow anaerobic filter-reactor and ozonation process

Abstract

The aim of the present study was to evaluate the efficacy of treating vinasse using anaerobic digestion (AD) followed by ozonation. The AD process was performed using a laboratory-scale upflow anaerobic filter reactor (UAFR) under continuous operation at 29 ± 1 °C. Stable conditions were reached at 10 kgCOD m-3 d-1 and a hydraulic retention time (HRT) of 5 days. Under these conditions, the efficiency of reduction of the chemical oxygen demand (COD) and the methane yield were 75.1% and 0.315 m3CH4 kgCODr-1, respectively. The anaerobically digested effluent was further treated using ozone in a bubbling column. An experimental 23 array [C(03)g= 70; 100 mgO3 L-1; pH= 7.5; 10; tc = 1 and 3 h] was used. The best conditions for effluent ozonation were 100 mgO3 L-1, pH 7.5 and 3 hours of contact with ozone. The average efficiencies for COD, color and turbidity reduction were 82.4, 93.8 and 99.3%, respectively.