The city of Doubtful (Problem 20-7) is considering the installation of thickening and de...

The city of Doubtful (Problem 20-7) is considering the installation of thickening and dewatering facilities. The revised flow diagram for Doubtful to include thickening and dewatering with appropriate return lines is shown in Figure P-20-9. Calculate a value for L in Mg/d. Assume that the appropriate values of η given in Figure 20-4 may be used when needed and that A = 7.250 Mg/d, X = 1.288 Mg/d.

Problem 20-7

The flow sheet for the Doubtful WWTP is shown in Figure P-20-7. Assuming that the appropriate values of η given in Figure 20-4 may be used when needed and that A = 7.250 Mg/d, X = 1.288 Mg/d, and N = 0.000 Mg/d, what is the mass flow (in kg/d) of sludge to be sent to ultimate disposal?