Effect of Volume Loading Rate (VLR) on Denitrifying Phosphorus Removal by the ABR-MBR Process

Abstract

The effect of volume loading rate (VLR) on denitrifying phosphorus removal was investigated in a continuous-flow ABR-MBR combined process treating domestic wastewater to arrive at optimum process parameters. In the experiment, the VLR of the ABR was set at 0.76, 1.01, 1.51, and 2.27 kg·(m3·d)-1. The removal of carbon, nitrogen, and phosphorus in the system and the effect of the VLR in the MBR on nitrification performance were observed for each VLR of the ABR. The results showed that under the condition when the VLR of the ABR was 1.51 kg·(m3·d)-1, the amount of COD removal in the A2 chamber was the largest, and shortcut nitrification was achieved in the MBR when the VLR of the MBR was 1.51 kg·(m3·d)-1. Meanwhile, the removal efficiency of NH4+-N and TN reached more than 90% and 72%, respectively, the anaerobic P-release and anoxic P-uptake were 7.41 mg·L-1and 15.42 mg·L-1, respectively, and the concentration of PO43--P in effluent was lower than 0.5 mg·L-1, which indicated that the shortcut nitrification was more conducive to strengthening the performance of denitrifying phosphorus removal in the ABR-MBR system.