Performance of Sequential Anaerobic/Aerobic Biological Treatment of Synthetic Wastewater Containing Two Types of Azo Dye

Abstract

In the present work, the ability of anaerobic/aerobic system in removing COD and two types of dye has been preformed. Four principal operating variables have been considered which are hydraulic retention time (HRT) of anaerobic and aerobic reactor, pH, and inlet dye concentration. All experiments are preformed under 35^o C. HRT for anaerobic reactor is (24, 36 and 48) hours while it is (20, 28 and 32) hours for aerobic reactor. pH are (6, 7 and 8) while the inlet dye concentration is (100, 150, 200) mg/l. Two dye types are used namely Acid Orange 12 (AO12) and Disperse Red 17 (DR17). The results showed that COD removal in anaerobic reactor increased with increasing HRT for both dyes and the max COD removal is (64.3%) and (60%) while max dye removal is (89%) and (88%) for DR17 and AO12 respectively at HRT of 36 hours. Aerobic reactor gives max COD removal of (85%) and (83%) and max dye removal is (65%) and (44.6%) for DR17 and AO12 respectively. The results also indicated that max COD removal is (64.3%) and (59.2%) and max dye removal is (89%) and (88%) for DR17 and AO12 respectively. However, max COD removal is (64.3%) and (60%) and max dye removal (89%) and (87.8%) at pH (7) for DR17 and AO12 respectively.