Abstract

RINCON, Nancy et al. Optimum time of hydraulic retention for the anaerobic treatment of light oil production wastewater. Rev. Téc. Ing. Univ. Zulia [online]. 2002, vol.25, n.2, pp.90-99. ISSN 0254-0770.

UASB reactor of 4 l was used under mesofilic conditions to degradate oil production wastewater from the light oil of Venezuelan industry. Several hydraulic retention times were used to change the organic load on the system. The carried out analysis during the experimentation were: organic matter removal as COD total phenol removal, methane production and volatile fatty acid (VFA) production. The investigation demonstrated that the optimum retention time for the treatment system for this type of wastewater was found to be 15 h, corresponding this to an organic load of 2 KgCOD/m³d, condition in which de COD removal and methane percentage were over 80% and the total phenol removal of 60%. For a retention time under 10 h, an inhibition from the methanogenic bacteria was observed, due to the high concentration on VFA, which limits the organic matter transformation present on the crude light oil wastewater to methane.

Keywords : Hydraulic retention time; anaerobic; production wastewater; UASB; light oil.