ORCID Identifier(s)


Graduation Semester and Year




Document Type


Degree Name

Master of Science in Civil Engineering


Civil Engineering

First Advisor

Habib Ahmari


This thesis presents a laboratory investigation focusing on the use of expanded shale as a filter media in bioswales. Bioswales are known for their effectiveness in improving water quality by removing pollutants such as total suspended solids (TSS) and turbidity. While conventional filter media with rocks, sand, and mulches have been utilized in bioswales to enhance infiltration capacity, the potential of expanded shale as an engineered media has not been thoroughly assessed and documented. The study conducted a series of thirty experiments involving three different flow conditions to mimic typical Best Management Practices (BMP) applications. The primary focus was on investigating the efficiency of the swale constructed with expanded shale in removing TSS and turbidity, which are key indicators of stormwater pollutants. The experiments were carried out in a rectangular flume measuring 15 feet in length and 4 feet wide, filled with expanded shale media with thicknesses of 6 inches and 4 inches. The study presented the performance of two different types of expanded shale with varying gradations, fine and coarse sizes. Additionally, the impact of influent concentration on the expanded shale media's effectiveness was examined, and two scenarios representing bioswales with and without an underdrain system were studied. The results demonstrated that expanded shale was highly effective in removing both TSS and turbidity under all tested conditions. The mean weighted average removal efficiency of TSS was found to be 42%, 43%, and 68% for the middle section of the channel, overflow, and infiltered flow, respectively, with a range of 20% to 75%, 19% to 75%, and 55% to 82%. Similarly, mean weighted turbidity removal was 17%, 15%, and 40% for the middle section, overflow, and infiltered flow, respectively, with a range of -4% to 43%, -7% to 49%, and 22% to 61%. Approximately 42% of TSS and 17% of turbidity removal occurred within the first half of the flow length. Due to the sedimentation process, coarser particles were observed to settle along the flow length of the flume. However, the particle gradation of the suspended sediment remained constant with time at a specific sampling location. Overall, the results indicated that greater filter media thickness, coarser expanded shale materials, and lower inflow rates consistently resulted in higher removal efficiency. Moreover, the influent concentration did not significantly impact the treatment efficiency of the expanded shale media. This study highlights the promising potential of expanded shale as an effective filter media in bioswales for enhancing water quality by removing pollutants such as TSS and turbidity.


Stormwater, BMPs, Bioswale, Expanded shale, Water quality, Suspended sediment, Water treatment


Civil and Environmental Engineering | Civil Engineering | Engineering


Degree granted by The University of Texas at Arlington

Available for download on Thursday, August 01, 2024