Nutrient removal in an electrically enhanced membrane bioreactor

Integration of the membrane bioreactor (MBR) into wastewater treatment facilities has gained popularity in recent years due to increasingly stringent discharge permits. However, up to now no research has been conducted on the combination of nitrification, denitrification and electrochemical phosphorus removal into a MBR system. In this study a novel electrically enhanced MBR (EMBR) system was used. Without pH adjustment and external carbon source supplementation, using synthetic feed, ammonium-nitrogen was completely eliminated; COD, total nitrogen and ortho-phosphorus were removed by 94.3%, 77% and 86.6%, respectively. The power consumption was 0.22 kW/m(3) of the influent synthetic wastewater. With a control MBR run in parallel, the applied voltage gradient of 1.82 V/cm did not exhibit adverse influence on the microbial growth. This system has the potential to achieve phosphorus removal through alternating the direct current intensity.