Modeling mass removal and sediment deposition in stormwater ponds using floating treatment islands: a computational approach

Abstract

Floating Treatment Islands (FTIs) offers effective solutions for stormwater management, providing ood attenuation and pollutant removal capabilities. However, there remains a knowledge gap concerning their performance, speci cally in terms of pollutant removal and sediment deposition. To address this gap, the present study employs Computational Fluid Dynamics (CFD) modeling to investigate the intricate interactions within FTI systems. Various FTI con gurations are analyzed, considering mass removal through FTIs and sediment deposition. The ndings demonstrate that FTIs have a signi cant in uence on ow patterns and mass removal. Notably, FTIs enhance mass removal compared to the control case, with larger sediment particles exhibiting higher removal rates. The correlation between the short-circuit index and sedimentation in FTI ponds highlights the potential of FTIs as indicators of treatment e ciency. Furthermore, the study focuses on mass removal exclusively through the FTI root zones. The positioning of FTIs within the pond has a considerable impact, resulting in differences of up to 20% in mass removal. Moreover, the FTI con guration exerts a more pronounced in uence on mass removal through FTIs than through sediment deposition alone. In cases where both processes occur simultaneously, the presence of FTIs lead to higher mass removal, primarily attributed to the FTIs themselves, particularly in the initial segment. Remarkably, certain FTI con gurations enable mass removal exceeding 70% for large sediment particles, even with a pond length less than half of the original.