Author(s): Haojie Lai, Guojian He, Wei Cheng, Lei Huang, Hongwei Fang
Linked Author(s): Haojie Lai
Keywords: Biofilm, bedform dynamics, suspended sediment transport, mathematic model
Abstract: Sediment erosion, transport and deposition play an essential role in the natural river succession, pollutants transport and habitats changes. Mathematical modeling is an effective tool to enhance our understanding of suspended sediment transport. Previous models for suspended sediment transport have been proposed based on clean sediment without biological process. However, sediment is pervasively coated by microorganisms and extracellular polymeric substances (EPS), which significantly increase erosion threshold due to the role of biological cohesion. In this paper, a mathematical model for flow and suspended sediment transport for biofilm coated sediment (bio-sediment) is proposed. In the hydrodynamic module, the bed resistance and bedform dynamics for bio-sediment are applied to the river bed boundary. In the suspended sediment transport module, the critical erosion velocity, settling velocity and reference concentration for bio-sediment are integrated for suspended sediment transport. The proposed model is applied to flume experiments for bio-sediment and results show that the proposed model can reasonably reflect the flow and suspended sediment transport with biofilm coating
Year: 2017