To study the impact of the accidental release of 1.6 tons of Chlorine gas in surrounding areas from a horizontal cylindrical tank lasting for one hour.
The impact is studied using standard dispersion modeling techniques considering various locations with different surface conditions in different seasons and meteorological conditions. Also, having direct measurements translates into high data transparency. The affected areas that are harmful to human exposures at different levels are detected. The affected areas are divided into three levels of concern, namely red zone, orange zone, and yellow zone. There are multiple methods to do this, including analytical methods. Analytical methods help to better understand current limitations and to challenge existing ones.
Dispersion analysis is a crucial tool used to assess the spread and impact of pollutants in the environment. It helps in understanding how contaminants disperse and how they can potentially affect human health and the overall environment.
Analytical methods play a significant role in dispersion analysis, helping to determine the concentration of pollutants in the air at various locations. These methods are based on mathematical equations and models that take into account factors such as wind speed, stability conditions, and the physical properties of the pollutant.
There are several widely used analytical methods for dispersion analysis, including:
The Gaussian plume model is one of the most commonly used dispersion models. It assumes that the pollutant disperses in a Gaussian-shaped plume, with the highest concentration at the center and gradually decreasing towards the edges.
The box model is a simplified dispersion model that considers the pollutant as confined within a box-shaped area. This model assumes that the pollutant is uniformly mixed within the box and does not consider the wind speed or direction.
The Lagrangian model is another widely used analytical method for dispersion analysis. Unlike the Gaussian plume and box models, the Lagrangian model follows the individual movement of particles or molecules in the pollutant plume. It takes into account the wind speed, direction, and movement of individual particles to estimate their concentration at different locations.
The Eulerian model is a grid-based analytical method that divides the environment into grids and calculates the concentration of pollutants at each grid point. This model considers the wind speed, direction, and other meteorological factors to simulate the dispersion of pollutants in the environment. It is often used for large-scale dispersion analysis.
After the Dispersion Analysis, the length of the red zone (average chlorine concentration in 60 minutes is more than 20 ppm) has been estimated to be 1.1 kilometers, the Orange zone (average chlorine concentration in 60 minutes is more than 2 ppm) 3.6 kilometers, and the yellow zone (average chlorine concentration in 60 minutes is more than 0.5 ppm) 7 kilometers, respectively downwind from the source.
With all other conditions constant, a threat zone is likely to be smaller with increasing ground roughness and wind velocity.
The length of a threat zone is likely to rise with increasing temperature as temperature affects atmospheric stability.
