14
Iydrofoil
E OCyinder
a 6
4
0 2
0 20 40 60 80
Velocity (cm/s)
Figure 2-2: Estimated head-velocity relationships for two different PSFM devices.
Larger head differences are produced at a given velocity using the known X
values for a cylindrical PSFM.
2.1.2 Flux Determination Under Steady State Conditions
Under steady state conditions, it is assumed that v vo, and the solute
concentration in the water are constant throughout the time of the measurement. When
these parameters are held constant, water flow through the cartridge, Qc [L3/T], can be
measured by calculating the relative amount of resident tracer remaining on the cartridge.
If the assumptions of linear, instantaneous, reversible sorption of the tracer are met, then
Qc may be calculated as follows
(M4,- 1)AOR,L
Qc = -(2-5)
t
where M,r [-] is the relative mass of the tracer remaining after elution time t [T]
(determined by quantitative analysis of the cartridge) with respect to the initial mass of
the tracer, A [L2] is the cross-sectional area of the cartridge, O [-] is the porosity of the
media, Rt is the retardation factor of the tracer and L [L] is the length of the cartridge
(Klammler et al., 2004).