Anaerobic horizontal flow reactor with polyethylene terephthalate as support material

A pilot anaerobic reactor was installed to remove the organic load of wastewater from dairy industry. It uses a bacterial inoculum previously acclimated to the substrate. It was disposed horizontally and filled with pieces of polyethylene terephthalate (PET), from plastic bottles. The reactor was operated at room temperature, during 100 days, in three phases: 1) the reactor was stabilized with volumetric organic load from 0.013 to 0.500 kg/day.m(3); 2) the hydraulic retention time was of 1 day and the volumetric organic load of 3 kg/day.m(3); 3) the volumetric organic load was incremented from 4 to 6.6 kg/day.m(3) and the hydraulic retention time was 1 day. Organic material removal efficiencies was of 85%, and approximately 75% were obtained in the second and third phase, respectively. The Y value was 0.15, indicating that 0.15 kg of biomass were generated by kg of QDO supplied to the reactor. Finally, the biomass generated inside the reactor was analyzed, obtaining a value of 18868 mg/L, which is a higher value than those of conventional systems.