Kinetic Model of an UASB Reactor Treating Low-Strength Wastewater

A substrate degradation kinetic model. incorporating the temperature effect, was constructed to simulate the operation of an UASB reactor treating a low-strength wastewater. Data from an UASB reactor was used to validate the model and fine tune the constant parameters. The reactor was operated at 3.0-8.7 h HRT and 15-29°C to acheive a COD removal efficiency between 71.9 and 88.5%. The substrate degradation followed the first order reaction. Through computer-aided curve-fitting technique, the declining growth constant, K2, were determined as 1.9 × 10-3. 2.4 × 10-3 and 2.6 × 10-3 L/mg VSS/d at temperatures of 17.2, 22.3 and 26.4°C, respectively. The activition energy, E. was 3.07 × 104 J/mol, indicating that the granular sludge in the UASB reactor was less temperature sensitive than conventional suspended-growth reactors.