Continuous monitoring and modeling of sediment settling characteristics in mine drainage using TSS measurements

Abstract

Batch settling column tests are among the most effective and practical methods for assessing sedimentation characteristics. These tests measure the settling velocity of the interface between suspended solids and the supernatant, providing insights into the overall sedimentation behavior. However, they are limited in their ability to capture localized sediment dynamics within the column. Additionally, traditional batch settling tests can be prone to errors, such as misinterpretation of the interface between the clear supernatant and settling particles, or subjective readings by operators. In this study, we present a novel experimental apparatus and methodology that enables continuous monitoring of sediment characteristics, allowing for the identification of shifts in sedimentation behavior. This method was applied to mine drainage sludge, and the results revealed a time-resolved distribution of total suspended solids throughout the column. A key outcome of this work is the identification of critical transition points in sedimentation behavior, which informed the development of a schematic model depicting the spatial and temporal distribution of settling types within the column. This model offers predictive insights into sediment behavior in batch settling columns and has potential applications in optimizing the design and operation of full-scale sedimentation tanks for various engineering and environmental purposes.