Computational Fluid Simulation to assess the environmental impact on rivers caused by industrial wastewater discharges

SITRA, as a leading company in industrial water treatment, is constantly facing different challenges in the proper design and implementation of its facilities. This is especially important when the treated water must be discharged into a sensitive environment such as the public water domain.

Under inland water legislation, any discharge of pollutants directly or indirectly into inland waters, as well as into the rest of the Public Water Domain, is considered a discharge, regardless of the procedure or technique used. One of the most important parameters to consider when a discharge occurs is the mixing zone. The boundaries of this zone determine whether the water meets environmental quality standards or, conversely, whether it is unsuitable for consumption. Its extent can be calculated in different ways: using expressions verified and accepted by the US Environmental Protection Agency (EPA), specific two-dimensional simulation software, and computational fluid dynamics (CFD).

Computational Fluid Dynamics (CFD) is a branch of fluid mechanics that allows for the detailed 3D calculation of fluid behavior under a wide range of conditions. In the case of discharges into rivers, due to the technical and economic limitations of experimental measurements and online monitoring for understanding the dynamics of pollutants transported in the river, CFD simulation emerges as a complementary and highly useful technique capable of calculating the evolution of the pollutant plume and evaluating the resulting environmental impact. With these tools, it will be possible to understand, detect, reproduce, and analyze in 3D the mixing and reaction of pollutants under different river operating scenarios.

Based on a series of parameters that define the boundary conditions of the case study: flow rate, characterization of the discharge, location of points of interest, among others, the environmental impact on the receiving environment can be calculated under different operating flow rates of the river (normal regime, dry season, etc.).

To meet these challenges, SITRA has the invaluable collaboration of Hydrens, the Grupo Gimeno company specializing in CFD simulation and other complementary techniques, which aims to offer innovative technological solutions based on improving fluid behavior to increase process performance, and is highly specialized in CFD simulation and other complementary techniques.