Simulation of granulation index and its utility for predicting percentage granules in UASB reactors

Abstract

This paper researches on the development of a dimensionless number for predicting percentage granulation in Upflow Anaerobic Sludge Blanket (UASB) reactors for treating biodegradable wastewaters. A Biomass Granulation Index (BGI) has been framed based on the experimental work conducted using laboratory scale UASB reactors. This index depends on mixing in the sludge bed, induced due to biogas and superficial upflow velocity of wastewater in UASB reactors. For obtaining proper granulation (percentage granules greater than 50%) resulting in higher Chemical Oxygen Demand (COD) removal efficiency, this paper recommends to design UASB reactors with BGI in the range of 240-560.