Dynamic Modeling of the Efficiency in a Uasb Reactor for Milk Wastewater Treatment

There is a need to develop methodologies enabling one to determine UASB reactor performance, not only for designing more efficient UASB reactors but also for predicting the performance of existing reactors under various conditions of influent wastewater flows and characteristics. In this work dynamic mathematical models for the prediction of the efficiency of a UASB reactor were developed. The dynamic modeling technique was applied successfully to a three-month data record from a laboratory milk wastewater treatment UASB reactor. The technique used included regression analysis by residuals. 11 parameters were examined including the following: % COD efficiency, influent COD, COD reduction, biomass produced, biogas production rate, % methane in biogas, alkalinity, reactor's temperature and RedOx, recirculation vessel's temperature and pH, and each parameter with a time lag of up to 3 days. Finally, after all parameters and all time lag trials two were the best fitted models that were developed. The models' adequacy was checked by X 2 test and F test for a data record of the same UASB reactor but at a different time period and proved to be very satisfactory. Additionally, the model's ability to predict and to control the plant's operation was examined. Simulation results thus obtained were carefully analyzed based on qualitative understanding of UASB process and were found to provide important insights into key variables that were responsible for influencing the working of the UASB reactor under varying input conditions.