UBC Theses and Dissertations
Dynamic modeling and process design of a membrane enhanced biological phosphorus removal process Al-Atar, Eman
The design and operation of the membrane enhanced biological phosphorus removal (MEBPR) process was studied in the current research to utilize the utmost capacity of the membrane system for operating the process under high influent loads. The study was conducted in two parts. In the first part, a dynamic model was calibrated to predict data collected from the UBC MEBPR pilot plant. Then the calibrated model was utilized in simulation studies to develop guidelines for the design and operation of a UCT-type MEBPR process under high flowrates without jeopardizing the effluent quality. The Technical University of Delft model combined with ASM2d model (TUDP) which is developed for conventional biological phosphorus systems was found sufficient to describe the process behavior of the MEBPR process. The trend of the measured concentration profiles were reasonably predicted, but the exact concentration values for the anoxic nitrate and the effluent ortho-phosphate were not predicted. The calibrated model for the MEBPR process was able to predict the measured data collected from the UBC conventional enhanced biological phosphorus removal (CEBPR) process without changing any of the model parameters except for the rate of polyphosphate formation, k[sub pp], which was increased from 0.1 to 0.2 g P/(g COD • d) to better predict the anoxic ortho-phosphate concentrations. Simulation studies for the UCT-type MEBPR process showed that the sludge mass distribution in the bioreactor zones of the anaerobic and the aerobic zone are critical for the bio-P removal and the nitrification processes respectively. Appropriate design of the bioreactor zone volumes is important to ensure proper sludge mass distribution in the biological zones. A constant influent volatile fatty acid to total phosphorus concentration was also found important for an efficient bio-P removal process. The aerobic recycle flow was found to be most important for reducing the effluent nitrate concentration while minimizing nitrate leakage to the anaerobic zone. Based on the experimental results and the simulation studies carried out in the current project, a set of guidelines for the design and operation of a UCT-type MEBPR process and the application of process control were developed to achieve stable process performance for nutrient removal under high flowrate operation.
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