Biological processes are the cheapest and most successful technique for achieving a defined effluent standard for large volumes of effluent. The advent of mathematical modeling has advanced the tertiary wastewater treatment. Superpro-2 (using Monod's kinetic model) and SASSPRO (based on the UCT model) are two window-based software packages which make it easier to apply these models. Superpro-2 is a powerful package very useful for designing purposes, while SASSPRO is more suitable for process evaluation, monitoring and updating due to the availability of multiple design features. Even though based on different models; they produce compatible outputs when simulation was performed for a Sewage treatment plant using a Conventional and. the Bardenpho configuration for biological nutrient removal. Thorough understanding of the biological processes and. availability of accurate kinetic data is essential for effective utilization of these packages.
Removal of nitrogen and phosphorous from wastewater by biological means has gained much recognition especially after IAWPRC (International association of Water Pollution Control Research and Control Model) assembled a task group on mathematical Modeling for the design and operation of Biological wastewater treatment. The model developed is capable of carbonaceous oxidation, nitrification, denitrification and also excess phosphorous removal. 'These models in matrix format describing complex systems are difficult to follow the author's ideas and the interaction between various components. The use of these models is diff.icult unless converted to computer.packages.
SASSPRO (Steady State Activated Sludge Simulator, Program), a computerized version of the University of Cape Town (UCT) model is good step in making the application of models easier.