1D Numerical Modeling of Sediment Pattern in Settling Basins

Document Type : Research Article


1 Department of Civil engineering, Zanjan Branch, Islamic Azad University, Zanjan, Iran.

2 Department of Civil engineering, North Tehran Branch, Islamic Azad University, Tehran, Iran.

3 Department of Civil engineering, Ghiaseddin Jamshid Kashani Higher Education, Iran


Settling basins are one of the most important structures, which are commonly used for deposition of sediment particles in water and wastewater systems in order to prevent the damage of sediment particles. The purpose of this study was to provide a one-dimensional numerical model for simulating flow and sediment in a rectangular settling basin. The governing equations are depth averaged equations of flow and sediment transport. In order to the numerical solution, the finite difference method has been used. The model can be used for non-uniform flow and non-uniform particles and may predict important information such as removal efficiency, thickness, and distribution of particle size of sludge. Comparison of the results of the proposed numerical model with the results of other researchers stated the acceptable accuracy of the proposed model, so that in all cases the error rate was less than 3%. The results of the sensitivity analysis showed that more than 50% of suspended sediment was deposited at the first 5 meters of the basin; therefore, the increase in the dimensions of the rectangular reservoir was not the best way to improve the performance of the pond. In fact, increasing the removal efficiency can be achieved by reducing the depth of the settling basin, increasing the cross-sectional area of flow and reducing the surface loading rate.


Main Subjects

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