C = Mco (2.17)
r 2L(1 mR,cont Rcont
where
Moont = mass of contaminant sorbed (mg)
r = radius of the flux meter cylinder (cm)
L = length of sorbent matrix (cm)
mR,ont = relative mass of hypothetical resident tracer retained after time period t.
Reont = retardation of sorbent (contaminant) on matrix (L g')
0 = water content in the device.
To calculate the amount of tracer retained in the flux meter (mR,cont) that is required
for contaminant flux calculations (equation 2.17), an imaginary tracer is assumed in the
flux meter that has the same leaching properties as that of contaminant (i.e. the tracer and
contaminant have the same retardation factor). Equation 2.13 and 2.14 can then be used
for calculating mR,cont using the parameters of sorbent matrix.
Service
Area of sorbed
contaminant
~~ ---------~-- --t------------ ----------
Figure 2-1 Contaminant sorbed by the sorbing matrix
Since the calculated concentration is same in the aqueous phase of the aquifer and
aqueous phase of the device, it can be directly used to calculate the contaminant flux
using
J = qo. C
(2.20)