JWSS - Journal of Water and Soil Science

Settling basins are one of the most essential structures for the separation of inflow sediments. This structure is established to enhance the water quality after the river-basins and water channels. Numerous studies have been conducted on the design of this structure and different methods have been provided to increase its efficiency. However, the use of simple settling basins with the minimum cost which can provide the ideal targets has been the focus of designers. In this study, the effect of flow-guiding plates and the angle between these and the inflow, and the impact of water depth in the basin on the trap efficiency of the settling basins were considered. For testing, 4 blades with specific length and angle were installed. This experiment was repeated for 3 different lengths and 3 angles. The results of the experiments showed that with the enhancement of the depth of water to 10 centimeters to 30 centimeters, while the basin had no flow-guiding plates, increased the trap efficiency of the basin by 4.9 percent. Also, by the use of flow-guiding plates in the suitable and best length and angle (in this study, the suitable size of blades was 22.5 centimeters and the best position was by the angle of 30 degrees); with the maximum of the water depth of 30 centimeters, the trap efficiency was increased by 13.3 percent. The sensitivity analysis done showed that the depth of water had the most effect on the trap efficiency of the basin and the changes in the lengths and angles of the blades position had the similar effects of the basin trap efficiency.