Applications of Equilibrium Thermodynamics - Elements of Environmental Engineering: Thermodynamics and Kinetics - page 178

4.13 2 Thesolubilityofpyreneinanaqueoussolutionofpolystyrenelatexcolloids
is given below:

[Latex], mg/L [Pyrene], mg/L

0 90

5 340

10 440

15 650

20 880

Obtain the value of the partition constant for pyrene on latex col-
loids.Assume that latex is 100% organic carbon and estimate the partition
constant from all reasonable correlations. Compare your results and
comment.
4.14 2 In a field study, a nonadsorbing (conservative) tracer (chloride) was
injected into a groundwater aquifer (unconfined and relatively homoge-
neous) along with two adsorbing organic compounds (carbon tetrachloride
and tetrachloroethylene). A test well 5 m downstream from the injection
well was monitored for all three compounds. The average time of arrival
(breakthrough time) at the monitoring well was 66 days for chloride ion,
120 days for carbontetrachloride, and 217 days for tetrachloroethylene.
(a) Obtain from the above data the retardation factors for the sorbing
compounds.
(b) Obtain the field-determined partition constants. The soil organic
carbon is 0.02.
(c) Comparewith K d obtainedusingthecorrelationofCurtisetal.(1994)
given in text. Explain any difference.
4.15 3 The bioconcentration factor can be predicted solely from the aqueous
compatibility factor (measured as solubility). Derive an appropriate rela-
tionshipbetweenthetwofactors. Howdoesitcomparewiththepredictions
using K ow ? Use pyrene and benzene as examples. For a fish that weighs
1.5 lb, how much pyrene can be accumulated within its tissue?
4.16 2 It is desired to remove benzene from an aqueous waste stream at an indus-
trial waste site that produces approximately 20,000 gallons of water per
day with a pH of 5.3 and a benzene concentration of 2000 μ g/L. A batch
adsorption system is to be used. A preliminary bench scale analysis was
conducted to get the adsorption data of benzene on two types of carbons
(I and II) at pH 5.3. The data are given below:

Carbon Initial Aqueous Final Equilibrium

Dose (mg/L) Concentration (mg/L) Concentration in Water (mg/L)

I II

96 19.8 14.2 12.5

191 19.8 10.3 12.0

573 19.8 6.2 11.0

951 19.8 5.8 9.0

1910 19.8 4.0 5.0