Fig. 3. Breakthrough curves calculated using the convection-dispersion equation subject to different boundary conditions for treatments where the injected solute was assumed to be normally distributed with 2 of 5, 10, 20, and 40% of L. Treatment denoted as 0% represents an injected solute distribution described as a Dirac delta function. In all cases, the total mass of solute injected = 1 mmol, porosity = 0.33, L = 37.5 cm, and Pe = 5.