Three-dimensional cylindrical lab-aquifer tank

Infiltration wells are a commonly used MAR technique for situations when large amounts of water must be infiltrated in a short time. However, many processes in the near-well surrounding still raise open questions. This concerns both, the influence of specific well parameters (diameter, filter slit width, etc.) on the infiltration performance as well as their influence on the clogging process. For a better understanding of these processes, a physical aquifer-well model was constructed and described in parallel by a numerical model (HYDRUS 2D/3D). The data obtained should ultimately be the basis for the development of tools for the assessment of clogging rates in infiltration wells. With the help of the tools it should be possible to optimize the operation of infiltration wells at the early planning stage.

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The physical model consists of a 1.20 m high glass fiber tank with a diameter of 1.00 m, which was filled up to a height of 1.10 m with sediment (total sediment volume = 0.87 m³). Sterile water is pumped with flow rates from 0.025 to 0.150 l/s from a 300 liter reservoir into a 1 inch infiltration well installed in the center of the model. The infiltrated water flows radially through the model and leaves the system at four outlets on five different levels (10 cm – 30 cm – 50 cm – 70 cm – 90 cm above the bottom of the tank). The water flows than back into the reservoir from the outflow column, which defines the piezometer height at the edge of the physical model.