Investigation of Aerobic - Anaerobic Integrated Bioreactor System for Treatment of Slaughterhouse Wastewater

Abstract

A pilot-scale aerobic–anaerobic Integrated process was constructed and implemented for reduction and removal of organic carbon and
nitrogen from the slaughterhouse wastewater. The advantages of this bioreactor include rapid biodegradation, low yields of sludge, and
excellent process stability. When the hydraulic retention time (HRT) was shortened to 48h, the average removal efficiencies for chemical
oxygen demand (COD), 5-day biochemical oxygen demand (BOD5), and total Kjeldahl nitrogen (TKN) reached 89.2%, 93%, and 39.2%,
respectively. The mixed liquor suspended solids (MLSS) in the effluent amounted to only 4.1±2.5 mg/L. The spatial changes in COD
measurements indicated that an oscillating change in COD between aerobic and anaerobic compartments occurred. the DO concentrations in
four aerobic compartments were 2.2 ±1, 4±1.0,6.2±1.2 and 8±1 mg L−1, respectively, and in the anaerobic compartments was all nearly zero.
MLSS in the compartments of bioreactor was 4.2±2, 9.9±2.5, 2.1±1.1 and 7.8±1.5, 1.6±0.8, 5±1.5, 1.2±0.9, 4.1±1.5 g L−1 along the flow
direction, respectively.