Loading...

Numerical modelling of soluble contamination transport in landfills based on empirical function of membrane efficiency

Hedayati Azar, A ; Sharif University of Technology | 2023

0 Viewed
  1. Type of Document: Article
  2. DOI: 10.1007/978-981-99-4041-7_18
  3. Publisher: Springer Science and Business Media Deutschland GmbH , 2023
  4. Abstract:
  5. Clayey soils are widely used as barriers to control leachate leakage in landfills. Chemico-osmosis is one of the important phenomena influencing soluble contamination transport through clay barriers acting as a membrane. The membrane ability to restrict contamination transport is referred to as membrane efficiency. Experimental reports have revealed that membrane efficiency is a function of soil void ratio and contamination concentration. However, the currently used empirical function expresses the membrane efficiency simply in terms of average concentration. Therefore, the merit of this study is to enhance the reliability of this function to take into account various concentrations and void ratios for Na-bentonite soil by using the dataset reported by Malusis and Shakelford (2002). In order to highlight the significance of the newly proposed function, a numerical simulation has been conducted to compare three different approaches of applying membrane efficiency including (1) constant, (2) point, and (3) average value. The results show that membrane efficiency from the point approach is less than the constant value at shallower depths but more at deeper depths in the early years. More importantly, membrane efficiency by point and average approaches decrease over time, resulting in higher contamination concentration compared to a constant value. The implication is that current design practice based on constant membrane efficiency is not conservative. According to the results of time-dependent contamination concentration, the required thickness and an efficient lifetime of the landfill barriers should be adjusted by simulation results of more reliable point and average approaches. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2023
  6. Keywords:
  7. Contaminant transport ; Membrane efficiency ; Numerical modelling ; Solute-clay interactions
  8. Source: Lecture Notes in Civil Engineering ; Volume 370 LNCE , 2023 , Pages 183-198 ; 23662557 (ISSN); 978-981994040-0 (ISBN)
  9. URL: https://link.springer.com/chapter/10.1007/978-981-99-4041-7_18