- Part 3 Modeled Tce Breakthrough Curves An Excel Worksheet Provided Breakthrough Times Xls Estimates Concentrations 1 (96.49 KiB) Viewed 47 times
- Part 3 Modeled Tce Breakthrough Curves An Excel Worksheet Provided Breakthrough Times Xls Estimates Concentrations 2 (163.06 KiB) Viewed 47 times
- Part 3 Modeled Tce Breakthrough Curves An Excel Worksheet Provided Breakthrough Times Xls Estimates Concentrations 3 (8.33 KiB) Viewed 47 times
but explain to me what I need to input into what exactly as I am
confused. The first equation is the
C vs t with retardation and the second equation is C
vst
Part 3: Modeled TCE Breakthrough Curves. An excel worksheet (provided, Breakthrough Times.xls), estimates concentrations in the x direction, which we will define as the prevailing direction of flow. Depending on what version of excel that you use, you may get an error message. Just press OK. This spreadsheet uses an analytical solution of the Advection- Dispersion equation for TCE in 1-dimentions. Enter the appropriate values into the Input Parameters table. This model assumes an original concentration is 1,000 ug/L (Co), a hydraulic conductivity of 400 ft/d (K), and an average gradient of 0.001 (i=). The graphs should update automatically. Answer the questions below.
1) Using the c vs. t tab, estimate when TCE concentrations will exceed the maximum contaminant level (MCL) of 5 ppb for all three distances (800, 1000, and 1200 ft)? 2) Do the same estimation as problem 1, but using the c vs. t with retardation tab? 3) Change the hydraulic conductivity in both tabs to 200 ft/d. How does this change the shape of the curves and what is the physical meaning? 4) Change the original concentration of TCE in both tabs from 1000 to 500 ppb. Does this change the shape of the breakthrough curves? Explain. 5) Reset the K and Co to their original values in both tabs. Now, change the 800 ft (x1) distance to 400 ft. Estimate the time at which the MCL is exceeded at 400 ft? 6) Using the tab of c vs. t with retardation replace the 1200 foot distance with the distance between each of the sources (A, B, and C) and the wells G and H. How long will it take for TCE concentrations to exceed the MCL? 7) Discuss any possible sources of error with using this simple approach (i.e., 1-Dimentional solution and aquifer properties)
Co 800 Input Parameters K= i = 0.001 n = 0.30 VX = 0.00 x1 = x2 = OLX = ft/day ft/ft (decimal) ft/day ug/L ft ft/day 1000 25 1E-06 0 feet feet feet x3 = D* = Dx = 1200 ft/day
1-D CONTAMINANT TRANSPORT OF TCE (CONCENTRATION VERSUS TIME) USING THE 2 OGATA-BANKS FORMULA 3 4 5 6 7 Input Parameters 8 K- ft/day Lug/L Pb = 2.00 g/cm Rf = 5.3 x1 = 800 feet 9 0.001 ft/ft CLX = 25 ft Koc = 152 ml/g Vc = 0.0 ft/day x2 = 1000 feet 10 n = 0.30 (decimal) D* = 1.0E-06 f?/day foc = 0.006 (decimal) x3 = 1200 feet 11 Vx= 0.0 ft/day Dx = 0 A2/day Kd = 0.912 ml/g 12 Co=