Turbidity reduction effect assessment for determination of sand dam fill material

Using the principle of the sand dam, the facility was installed in the upper stream area where water without supply in Korea. The sand dam aims to increase the water resources available during normal season and countermeasure for drought. The optimal filling material was selected to evaluate the turbidity reduction efficiency in the sand dam installation, and the applicability was evaluated by configuring a field-scale column experiment. Two sizes of columns were used for the experiment, and sand was used to increase the applicability of the sad dam filling material. A column with a height of 80 cm was used to select the filling materials. Four types of sand were used, and the actual turbidity reduction efficiency was analyzed by configurating a field-scale column of 125 cm height for a filler with a good particle size. The selection of filling materials was determined as a combination layer (0.8-1.2 mm / 2-4 mm), which is a sample with a high average turbidity reduction rate and uniformly reduced turbidity without large deviations. The turbidity reduction rate is more than 95% except for the first experiment, showing excellent performance. As the experiment proceeded, it was found that the porous filler material became smaller as the ocher piled up, and while the experiment was conducted without removing the ocher, the turbidity reduction effect was found to increase, but the outflow was reduced. Using the results of the experiment, it will be possible to increase the applicability of the field filling material. In addition, it can handle with various situations, and it seems possible to take a preemptive handle according to signs such as a decrease in the amount of outflow rate before complete blockage occurs.