Evaluation of performance in a combined UASB and aerobic contact oxidation process treating acrylic wastewater

Abstract

The lab-scale and full-scale performance of a combined mesophilic up-flow anaerobic sludge blanket (UASB) and aerobic contact oxidation (ACO) process for treating acrylic wastewater was studied. During lab-scale experiment, the overwhelmed volumetric load for UASB was above 6 kg chemical oxygen demand (COD) ·(m−3·d−1) since COD removal efficiency dropped dramatically from 73% at 6 kg COD·(m−3·d−1) to 61% at 7 kg COD·(m−3·d−1) and 53% at 8 kg COD·(m−3·d−1). Further results showed that an up-flow fluid velocity of 0.5 m h−1 for UASB obtained a highest COD removal efficiency of 75%, and the optimum COD volumetric load for the corresponding ACO was 1.00 kg COD·(m−3·d−1). Based on the configuration of the lab-scale experiment, a full-scale application with an acrylic wastewater treatment capacity of 8 m3 h−1 was constructed and operated at a volumetric load of 5.5 kg COD·(m−3·d−1), an up-flow fluid velocity of 0.5 m h−1 for UASB and a volumetric load of 0.9 kg COD·(m−3·d−1) for ACO; and the final effluent COD was around 740 mg L−1. The results suggest that a combined UASB–ACO process is promising for treating acrylic wastewater.