Page 408 - Soil and water contamination, 2nd edition

APPENDIX 2

Answers to exercises

CHAPTER 2

1. a. 100.2 mg l -1
b. 2.5 mmol l -1
c. 5.0 meq l -1

2. a.
Cations Concentration Anions Concentration
meq l -1 meq l -1
Na + 0.38 Cl - 0.06
K + 0.03 HCO 3 - 4.18
Ca 2+ 2.18 SO 4 2- 0.11
Mg 2+ 1.78 NO 3 - 0.08
H + 10 -4.5

-1;
-1
b. cations: 4.37 meq l ; anions: 4.43 meq l there is a surplus of anions (0.6 percent of
+
the total charge of cations and anions); H can be ignored.
c. 440 μS cm -1
d.
Cations Activity coefficient γ i Anions Activity coefficient γ i
Na + 0.92 Cl - 0.92
K + 0.92 HCO 3 - 0.92
Ca 2+ 0.72 SO 4 2- 0.71
Mg 2+ 0.73 NO 3 - 0.92

5. Cadmium concentration in:
water: 0.09 mg l -1
sediment: 6.9 mg kg -1
fish: 6.4 mg kg -1

10/1/2013 6:47:53 PM
Soil and Water.indd 407
Soil and Water.indd 407 10/1/2013 6:47:53 PM