University:
California State University, Northridge
Course:
ME 485 | Introduction to Environmental Engineering
Academic year:

2007
Views:

459

Pages:

4
Author:

kloriran5o

Mff'IK' SOLUTIONS· FOR CHAPTER 6 6. l Hardness in meq/L: 150mg I L "+ Ca- = 20.05mg I meq = 7 .5meq I L 60mo '+ 0 IL Mg- = =4.9meq/L 12.15mg/ meq Total hardness = 7.5 + 4. 9 = 12.4 meq/L Hardness asCaCO3: meq mo asCaCO, • = 622mg I Las CaCO1 Hardness = 12.4-- x 50 ° L rneq Table 6.5 would classify this as very hard water. 6.2 pH= 9, [ H".. ] = 10- pll = lx 10-9 mo! /L -<• lxlO -'> mol I g 10 mg meq + =----x--x----x--= Ixl o meq /L H ( ) L mo! o l mo:::, 0 meq mg CaCO, - 5 - 10·-<• x50 ------:,x 10- m 0 /L as CaCO .. meq L 1 ::i (OH-) = 10-5 mol L = 10-:? 17 g ICY mg meq =• 10_1 meq /L x-x x rnol g 17 mg meq L ·' x 50 mgCaC0 3 meq =0.5mg/LasCaCO, 6. 3 First, ignoring the contribution of H+ and OH- , with pH=I0.5, 39.0mg/L of CO32- and 24.5 mg/L of HCO3-, (l2+3x16) = 30_0 mg a. CO/• = 2 meq 39.0mg/L 50m x (co/-)= 30mg / rneq gofCa C0 3 meq =65mg/La sCaCOJ

Solutions for Chapter 6