Treatment and Reuse of Black Water by Novel Energy-saving Shaft/Anaerobic /Anoxic/ Aerobic (S/A/A/O) System: A Novel Energy-saving Shaft/Anaerobic /Anoxic/ Aerobic (S/A/A/O) System for black water

Abstract

In this study the novel integrated anaerobic/anoxic/aerobic (A/A/O) and shaft aeration process system which could enhance the nutrient removal efficiency of wastewater with a low carbon nitrogen ratio (C/N) was investigated. Several dissolved oxygen (DO) ratios (1.0-2.0, 2.0-3.0, 3.0-4.0 mg/L) were applied in order to obtain more knowledge on the biological nitrogen and phosphorus removal performances. The experiment was carried out on a lab-scale Shaft-Anaerobic-Anoxic-Aerobic (S/A/A/O) wastewater treatment system. The average removal efficiencies of the total organic carbon, total nitrogen and phosphorus were 84.0%, 82.0% and 93.7%, respectively. The result showed that the proposed system was promising for the treatment of wastewater with a low C/N ratio because that in this system nitrification and denitrification happened simultaneously. Besides, the system had an automatic return system and its floor area was small, which made it energy-saving.