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 o C and consequently decreased to 30 and 25 o C. For the volumetric loading rates examined i.e. 5-35 KgCOD m -3 d -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 o C respectively. Prediction of effluent COD and methane production rate during continuous reactor operation was possible using the first-order kinetic model.