Enhanced Nitrogen Removal by Rice Husk Amended Dynamic Membrane Bioreactors

Abstract

AbstractEffective and low-cost dynamic membrane bioreactors (DMBR) can be a strong option for wastewater treatment in developing countries. The goal of this study was to investigate the effect of rice husk addition on the DMBR’s nitrogen removal performance. Tests were performed at both lab-scale and pilot-scale facilities. Results showed that rice husk served as a suitable biofilm carrier as well as an effective denitrification carbon source. In lab-scale experiments, the removal efficiency of rice husk amended DMBR for chemical oxygen demand (COD), NH3-N, and total nitrogen (TN) was 96.7, 96.3, and 80.4%, respectively. Results from the pilot-scale DMBR system showed that removal efficiency for COD and NH3-N was 90.3 and 95.2%, respectively, whereas TN removal was comparatively lower (50.5%). Fluorescence in situ hybridization (FISH) analysis showed that the bacterial population was higher in the rice husk added DMBR than the controlled DMBR, and ammonia-oxidizing bacteria were the main components of tot...