Application and Evaluation of Removing Nutrients in Wastewater via AAO Process in Tianjin, China

Abstract

Anaerobic/Anoxic/Oxic (AAO) process is one of the effective measures to remove nutrients from the influents for most wastewater treatment plants in China, and thus, assessing the efficiency of AAO process is of great significance. This study used wastewater samples from Tianjin province in China to make evaluations of this technology. Componential analysis shows that total nitrogen (TN), ammonia nitrogen (NH3-N), and total phosphorous (TP) are crucial in determining the concentrations of nitrogen and phosphorous in Tianjin wastewater. The wastewater in Tianjin is mainly derived from domestic wastewater, and followed by industrial one. Decontamination efficiency analyses show that AAO process can remove 79% of TN and 96% TP in the wastewater, which are high because it is manipulated to its maximum extent by the plant. Moreover, the concentrations of TN and TP in the effluents are 8mg/L and 0.12mg/L, conforming to the national standards in China. AAO process can also degrade BOD (Biochemical Oxygen Demand) from the wastewater, which is also a major pollutant in wastewater. The determining factor of the extensive application of AAO process in Tianjin is that it requires less money compared to its counterparts. Therefore, if similar wastewater sources are happening in other cities in China, AAO technology could be widely used there since it is effective both environmentally and economically.