Hydrodynamic Analysis of an Eco-Trap to Improve Gross Pollutant Removal on Water Surface with CFD Simulation

The use of gross pollutant trap (GPT) as one of the primary treatment measures to remove coarse pollutants from water surfaces that should not enter sewers and waterways is widely recognized worldwide. Over the years, GPT designs have evolved significantly, from large and built-in devices to proprietary off-the-shelf products as a structural measure to curb river pollution. Nevertheless, most of the installed GPTs are poorly maintained, leading to many environmental problems such as odour, vermin, flooding and unsightly views. This study is interested in developing a removable gross pollutant trap, called Eco-trap, which can contribute to river cleaning without much complexity and cost. The hydrodynamic performance of the Eco-trap is evaluated using Computational Fluid Dynamics (CFD) simulations. To ensure the reliability of the simulations, grid independence tests were conducted with coarse, medium, fine and finer mesh sizes. Three different mesh sizes (0.10m x 0.05m, 0.20m x 0.10m and 0.30m x 0.15m) were tested in five velocity scenarios to evaluate their effectiveness in removing pollutants from stormwater runoff. The results provide important insights into the velocity distributions, pressure gradients and force distributions around and on the trap structure, which provides valuable information for optimizing the design of pollutant removal devices. By analysing the total deformation and equivalent stress, net weaknesses were identified for further improvements. This study contributes to the improvement of stormwater management in Malaysia by providing new insights into the hydrodynamic behaviour of gross pollutant removal devices and their potential applications to reduce water pollution in river ecosystems