Application of an anaerobic hybrid reactor for petrochemical effluent treatment

An anaerobic hybrid reactor (UASB/Filter) was used for petrochemical wastewater treatment in mesophilic conditions. The seeded flocculent sludge from a UASB plant treating dairy wastewater, acclimatized to the petrochemical wastes in a two-stage operation. After start up, under steady-state conditions, experiments were conducted at OLRs of between 0.5 and 24 kg TCOD m⁻³ d⁻¹, hydraulic retention times (HRT) of 4–48 h and up-flow velocities 0.021–0.25 mh⁻¹. Removal efficiencies in the range of 42–86% were achieved at feed TCOD concentrations of 1,000–4,000 mg L⁻¹. The results of reactor performance at different operational conditions and its relations are presented and discussed in this paper. Then, the obtained data are used for determination of kinetic models. The results showed that a second-order model and a modified Stover–Kincannon model were the most appropriate models for this reactor. Finally, the biogas production data were used for the determination of biogas production kinetics.