evaluation of a pilot aerobic reactor with polyetilenterephtalate (pet) as support material for dairy wastewater treatment

Abstract

A pilot aerobic horizontal plug flow reactor filled with pieces of PET (polyethylene terephthalate), from plastic bottles was installed for treatment of a synthetic substrate prepared from lactic whey with COD values of 800 to 2100 mg/L. A bacterial inoculum previously acclimated to the substrate was used. Organic material removal efficiencies of 62.2%, 85% y 94% were obtained with retention times of 5.14, 6.01 and 8.01 hours, and with volumetric organic loads (Lv) of 7.68, 6.19 and 4.61 kg/day.m3, respectively. Also, the kinetic mass transfer constant (k) was calculated and it presented a value of 0.02 m/day. On the other hand, an F/M ratio of 0.4 was determined, indicating that the process had a similar performance to an extended aeration system. Finally, the biomass generated inside the reactor was analyzed, obtaining a value of 11560 mg /L, which is a higher value than those of conventional systems.