Effect of the organic load in the performance the UASB reactor treating slaughterhouse effluent

Abstract

The behavior of a UASB reactor of 4 L was studied at mesophilic condition treating wastewater from' the meat industry. The organic loads (OL) of 1.82Ó 0.18; 3.21 Ó 0.27; 6.33: Ó 0.23; 8.40: Ó 0.19; 9.98: Ó 0.88 and 12.30: Ó 0.49 kg COD/m3d, were evaluated at hydraulic retention time (HRT) of 24 h. During the experiment the following parameters were monitored to evaluate the operation of the reactor: pH, alkalinity, chemical oxygen demand (COD), temperature, biogas production, methane content in the biogas, production ofvolatile fatty acids (VFA), total suspended solids (TSS) and volatile suspended solids (VSS). Each OL stayed until reaching the stability in the operational parameters of the reactor. The results demonstrated the efficiency of the UASB reactor to treat slaughterhouse wastewaters for long range OL (1.82 -12.30 kg COD/m3d). The COD removal percentage was 80% to OL 9.98 kgCOD/m3d to HRT of 24 h. The increment of OL affected significantly the variables evaluated, (except pH). A decrease in COD removal and methane percentage were observed, while the VSS, alkalinity and VFA concentration were increased.

Keywords

• slaughterhouse effluent
• UASB reactor
• anaerobic treatment
• mesophilic condition