Modelling the impact of a sewage treatment plant on a recipient (Colombia)

This research developed a methodology for assessing the interaction between the performance of wastewater treatment plants and their impact on receiving water bodies with a case study from a town in Colombia. The research used Aquasim software, a tool that performs simulations, sensitivity analysis and parameter estimations in wastewater. The reactors at the wastewater treatment plant were built as completely stirred tank reactors connected to each other in series and then the model was coupled with the river as the receiving water body to integrate the two systems. For the river sections, it considered them as River Section Compartments and used the effluent of the wastewater treatment plant as part of the influent for the river. To assess the effects of effluent discharge into the river, the impacts of nitrogen and phosphorus on the growth of phototrophs was monitored under different scenarios and it was found that discharging effluent into the river influenced the growth of phototrophs. As part of developing the methodology, the runtime of Aquasim was optimized by unrolling some of the calculation functions in the source code.