Activated sludge process is the most commonly used aerobic wastewater treatment system. It uses a culture of microorganisms that utilizes organic matter in sewage for its sustenance, growth and synthesis of new cells. Problems like sludge bulking and foaming are the serious issues in this systems, which is formed because of excessive filamentous growth, high F/M ration or due to poor settling of waste sludge. Some methods are there, for removing the sludge bulking which are quite expensive. The efficient and cheap way of sludge removal is using rice bran, since it has enough nitrogen and phosphorous, filamentous bacteria growth is suppressed and favourable microorganism growth is enhanced. The shortcomings such as low density structure and less sedimentation rate are rectified while using rice bran which is estimated by SSVI OR SVI test. Additionally, laboratory test were conducted which reveals nitrogen and phosphorous do not dissolve completely from the rice bran.
Dr. Geetha Srikanth and Kokila, M., “Waste Water Sludge Treatment Using Rice Bran”, Integrated Waste Management in India: Status and Future Prospects for Environmental Sustainability, Environmental Science and Engineering, pp. 133–138, 2016.