Effect of Media Packing Density on the Performance of Anaerobic Hybrid Reactors for the Treatment of Complex Phenolic Wastewater

Abstract

AbstractThe effect of media packing on the performance of anaerobic hybrid reactors (combining upflow anaerobic sludge blanket reactors and anaerobic filters) was examined for the treatment of simulated coal wastewater at four hydraulic retention times (HRTs) under mesophilic (27±5°C) conditions. PVC rings were used as filter media; they were maintained at varying packing densities in three experimental reactors (R1, R2, and R3) at 34.29, 24.29, and 14.13 kg m−3. Synthetic coal wastewater with an average chemical oxygen demand of 2,240 mg L−1 and concentration of phenolics of 752 mg L−1 was used as substrate. During the four-month operation, the HRT was shortened from 0.66 to 0.33 days. The removal of phenolics was favored in Reactors R1 (98−92%) and R2 (96–86%) more than R3 (94−82%) with the reduction of HRT. Biomass concentration of Reactors R1 and R2 increased from 42 to 69.7 and 64.7 g VSS L−1 with an increase in the density of the packing media. Microbial biomass distribution revealed the lowest ...