The recent developments in pollutant measurement methods and techniques necessitate improvements in modelling approaches. The models used so far have been based on seasonally averaged data, which is insufficient for making short-term predictions. We have improved the existing modelling tools for pollutant transport and dispersion on three levels. We significantly refined the numerical grid; we ...

Modelling pollutant dispersion in cities is challenging for air quality models as the urban obstacles have an important effect on the flow field and thus the dispersion. Computational Fluid Dynamics (CFD) models with an additional scalar dispersion transport equation are a possible way to resolve the flowfield in the urban canopy and model dispersion taking into consideration the effect of the ...

Based on the grey theory, grey characters of river environment system are analyzed, the velocity and dispersion coefficient and attenuation in river are considered as uncertainty parameters and expressed as gray parameters. A grey differential equation of contaminant diffusion in river is built. And the equation has special structure. The truncation error of finite differential method in solvin...

—we present in this work a numerical study of pollutant dispersion resulting from a bent chimney around twin obstacles placed in the lee side of the source. A three-dimensional numerical model with the turbulent Reynolds Stress Model (RSM) and a non-uniform grid system was used to examine the effects of a double tandem obstacle cubic on the development of the incoming flow. The results obtained...

Pollutants are trapped and accumulate within cold-air pools, thereby affecting air 5 quality. A numerical model is used to quantify the role of cold-air-pooling processes in 6 the dispersion of air pollution in a developing cold-air pool within an alpine valley under 7 decoupled stable conditions. Results indicate that the negatively buoyant downslope flows 8 transport and mix pollutants into t...

Study in surface water quality is important. Rivers are one of the main sources of water supply fordrinking, agriculture and industry. Unfortunately, sometime Rivers where wastewater dischargesare considered. For this reason,the pollutant transmission in river is one of the most importantproblems in Environmental Engineering. the Advection Dispersion Equation (ADE) is governedon the pollutant t...

A computer program was developed to predict the dispersion of gas pollutant in the atmosphere. This program relies on puff method, and in order to consider the wind shear effects, the program has the ability to consider the complete dynamic and unsteady atmospheric conditions. Plume rise of hot pollutants due to buoyancy effects was also considered. The program has the capacity to perform the r...

Water pollution by industrial and agricultural waste is an increasingly major public health issue. It is therefore important for water engineers and managers to be able to predict accurately the local behaviour of water-borne pollutants. This paper describes the novel and ecient coupling of dynamically adaptive hierarchical grids with standard solvers of the advection±di€usion equation. Adapti...

Many environmental conflicts involve pollutants such as greenhouse gas emissions that are dispersed through space and cause losses of ecosystem services. As pollutant emissions rise in one place, a spatial cascade of declining ecosystem services can spread across a larger landscape because of the dispersion of the pollutant. This paper considers the problem of anticipating such spatial regime s...

Pollutant distribution remains poorly understood when traffic tidal flows (TTFs) happen. By conducting computational fluid dynamic (CFD) simulations, the research efforts first focus on how different-side traffic-produced flow and turbulence (TPFT) affect in-canyon airflow corresponding pollutant dispersion. Second, composite effects of non-uniform emission TPFT are investigated. Finally, influ...