Pollutant Dispersion Modeling in Natural Streams Using the Transmission Line Matrix Method

Abstract

Numerical modeling has become an indispensable tool for solving various physical problems. In this context, we present a model of pollutant dispersion in natural streams for the far field case where dispersion is considered longitudinal and one-dimensional in the flow direction. The Transmission Line Matrix (TLM), which has earned a reputation as powerful and efficient numerical method, is used. The presented one-dimensional TLM model requires a minimum input data and provides a significant gain in computing time. To validate our model, the results are compared with observations and experimental data from the river Severn (UK). The results show a good agreement with experimental data. The model can be used to predict the spatiotemporal evolution of a pollutant in natural streams for effective and rapid decision-making in a case of emergency, such as accidental discharges in a stream with a dynamic similar to that of the river Severn (UK).

Impact of roughness changes on contaminant transport in sewers

“…Dispersion is a combination of molecular and turbulent diffusion, advection and shear (Meddah, et al, 2015). It is created by the non-uniformity of velocity fields related to the different characteristics of the stream such as geometry, roughness, and kinematics.…”

“…Predicting of pollution spread is important for the environmental protection. In the field of water quality modelling, several authors (Chapra, 1997;Fischer et al, 1979;Graf, 1998;Runkel and Broshears, 1991;Marsalek, et al, 2004;Meddah, et al, 2015) presented different approaches to understand and interpret the basic concept of water quality problems. In a case an accidental discharge in a stream, the prediction of the pollutant transport is crucial in effective and rapid decisionmaking.…”

Impact of Sediment Layer on Longitudinal Dispersion in Sewer Systems

“…Generally, prediction of the rate of pollution spreading is necessary for water quality protection management. Different authors have described various approaches how to better understand the concept of water quality problems and questions [11][12][13][14][15][16]. If an accidental pollution leak into a stream occurs, the prognosis of pollutant transport and spreading is necessary for rapid and effective implementation of the protective measures.…”

Assessing the Risk of Contaminant Dispersion From Fibrous Sediments of Industrial Origin

“…From this viewpoint, our research was designed to assess: (i) the degree to which contaminants disperse from the fiberbanks to the surrounding water system, while considering the uncertainties; (ii) if dispersion becomes a risk to the environment; and (iii) the dispersion path(s) that determine(s) risk. Pathways for dispersion include diffusion and advection (e.g., Meddah et al, 2015). Differences in chemical potential between sediment and pore water, and concentration gradients between pore water and overlying bottom water drive lake and sea diffusion processes of POPs (e.g., Schwarzenbach et al, 1993;Parnish and Mackay, 2020).…”