| Abstract: | The effect of uncertainty in system parameters and the accuracy of the mathematical model used on the design and reliability of the activated sludge process is investigated by Monte Carlo simulations. Simulations indicate that the coefficient of variation for a reactor volume varies from 0.56 for a single mixed tank reactor to 0.44 for a plug flow reactor. The coefficient of variation for effluent for reactors designed on nominal values was found to be 0.56 for a mixed-tank reactor, 1.28 for two reactors in series, 1.56 for three reactors in series and 1.6 for a plug flow reactor. Significant contributing parameters to the reliability of the process are established. Reactor volumes for desired reliability levels are also calculated. |
