Environmental Engineering Processes HW #6 Environmental Engineering Processes HW #5 (50 points) 1) For the following five systems calculate i) the axial / longitudinal dispersion coefficient (EL) in...

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Environmental Engineering Processes HW #6 Environmental Engineering Processes HW #5 (50 points) 1) For the following five systems calculate i) the axial / longitudinal dispersion coefficient (EL) in cm2/s, ii) the PeE and iii) the dispersion number, ND. For all problems assume a liquid density of 1.0 g/cm3, a viscosity of 0.01 g/cm-s and a liquid diffusion coefficient (D) of 1.0 x 10-5 cm2/s. a) Flow in a pipe; v = 1.5 m/s, d = 1.0 m and f = 0.08 b) Flow in a river v = 0.3 m/s, h = 2.0 m, w = 10 m and slope of 0.0001 c) Open channel v = 0.05 m/s, h = 1.5 m and w = 1 m d) Packed bed – sand filter Q = 10.0 m3/hr, cross sectional area of the filter Asc = 1.0 m 2 and dm = 0.1 cm e) Groundwater (two EL values) v = 1.0 x 10-4 cm/s the monitoring wells are 10.0 m and 100 m from the source and you assume that they are the length of the plume, LP 2) Using the solution to the advection–longitudinal dispersion equation (non-SS, w/o reaction) calculate the following for the response to a continuous step input of a tracer at a concentration C0: a) Concentration history in the groundwater for the conditions of part 1e above. Calculate C/C0 (0 to 1) versus time in days (1 to 2,500 days) at sample well locations of 10 m and 100 m (assume these are LP for this case). Use both the advection-dispersion formula equation (Logan, Eq 12-16) and the simplified form (Logan, Eq 12-17) as presented on page 2 and in class. Plot all four curves on one graph. For the plot use a log scale for time (10 to 10,000 days). Also include a small summary table with the C/C0 values at 100 days for X = 10 m and at 1000 days for X = 100 m using both equations Was using the simplified form (Logan, Eq 12-17) justified? b) Concentration profile in a river for the conditions of part 1b above. Plot C/C0 (0 to 1) versus distance downstream of the tracer addition after 2 hr, 5 hr, 10 hr and 20 hr (four curves on one graph). For the plot use a log scale for distance (1 to 100 km). Also include a small summary table with the distance travel at C/C0 =0.5 for all four times. This problem is much easier to do if you use a recent (post 2011) version of Excel, such as that used in the University computer labs.