PROBLEM 1

1
PROBLEM 1

• A certain soil has a bulk density of 1.28 g cm-3
  and an organic carbon content of 1. The porosity
  of the soil is 30, of which 50 is occupied by
  water and 50 by air. Using values from Table
  6-4, find the percentages of benzene and
  2-butanone contained within the solid, liquid and
  gas phases.

2

• a) benzene
• We need the following properties from Table 6-4
  KH 0.22 Kow 134.90.
• The concentration of benzene in the water (Cw) is
  not given we will carry this term throughout the
  calculation and it will cancel when we calculate
  mass percentages.
• We will need to calculate Kd from the formula
• Now, Cs is related to Cw by

3

• And the mass of benzene in the solid phase is now
• The mass of benzene in the water is given by
• The concentration of benzene in the air is given
  by
• And the mass by

4

• The total mass of benzene in the soil is
• benzene in solid 100(1.036Cw/1.219Cw) 85
• benzene in water 100(0.15Cw/1.219Cw) 12
• benzene in air 100(0.033Cw/1.219Cw) 3
• b) 2-butanone
• We need the following properties from Table 6-4
  KH 0.001 Kow 1.820.
• The concentration of 2-butanone in the water (Cw)
  is not given we will carry this term throughout
  the calculation and it will cancel when we
  calculate mass percentages.

5

• We will need to calculate Kd from the formula
• Now, Cs is related to Cw by
• And the mass of 2-butanone in the solid phase is
  now
• The mass of 2-butanone in the water is given by
  (note, it is the same as for benzene)
• The concentration of 2-butanone in the air is
  given by

6

• And the mass by
• The total mass of 2-butanone in the soil is
• 2-butanone in solid 100(0.014Cw/0.164Cw)
  8.5
• 2-butanone in water 100(0.15Cw/0.164Cw)
  91.4
• 2-butanone in air 100(0.00015Cw/0.164Cw)
  0.09