Evaluation of Influent Medium Composition and Concentration in a Batch Reactor for Effective Startup of UASB Reactors

Abstract

This study demonstrated the use of batch bioreactor experiments as an evaluation tool to determine appropriate influent medium composition and concentration for effective startup of an upflow anaerobic sludge blanket (UASB) reactor. Using seed sludge from a domestic treatment plant, the weight ratio of glucose and volatile fatty acids (VFA) present in the influent synthetic medium was varied and the batch performance was assessed in terms of pH variation during the course of the experiment, chemical oxygen demand (COD) reduction, specific substrate uptake rates, methanogenic activity, and methane yield. The performance was also evaluated by increasing the concentration of influent COD. Medium composition with glucose to VFA weight ratio at or below 2:8 and COD concentration at