Kinetic analysis and simulation of UASB anaerobic treatment of a synthetic fruit wastewater

An Upflow Anaerobic Sludge Bed (UASB) reactor was used to evaluate mesophilic anaerobic
treatment of a pre-acidified fruit wastewater. The system was operated at increasing volumetric
loading rates by sequentially increasing wastewater flowrate. The operational temperature was
maintained initially at 37 oC and consequently decreased to 30 and 25 oC. For the volumetric loading
rates examined i.e. 5-35 KgCOD m-3d-1), the UASB attained COD removal levels higher than 70%.
The first-order kinetics were found to be suitable for representation of the substrate removal. The
kinetic constant decreased from 23 to 21 and 19 d-1 at 37, 30 and 25 oC respectively. Prediction of
effluent COD and methane production rate during continuous reactor operation was possible using
the first-order kinetic model.