Adsorption - Principles of Chemical Separations with Environmental Applications - page 207

Column
outlet
solute
conc.

C a

V T pilot

Total volume of fluid through column

Figure 7.11 Outlet concentration vs volume throughput for pilot column.

The parameters needed to effect the scale-up are:

( BV ) = ( V p ) Q / Q p = Bed volume of design column, where Q is the fluid volumetric

flowrate of the design column

M = ( BV )( ρ s ) = mass of adsorbent in the design column ( ρ s = adsorbent bulk

density)

V pilot
T

= breakthrough volume of the pilot column (chosen to correspond

to the maximum allowable effluent solute concentration). This
volume is the total amount treated before breakthrough occurs
in the pilot column.

V pilot
T
M pilot

V B =

= volume of liquid treated per unit mass of adsorbent (same for

both columns)

V T =

M t = Q / mass of adsorbent exhausted per hour in design column Q .

t bt = M / M t = breakthrough time for the design column

V T = Qt bt = breakthrough volume for the design column.

Example 7.1: Fixed-bed column design by the scale-up approach

Problem:
A wastewater flowrate of 180 m 3 / day has a TOC (total organic carbon level) of

200 mg L. A fixed-bed GAC adsorption column will be used to reduce the maximum

effluent concentration to 8 mg

/

L. A breakthrough curve, Figure 7.12, has been
obtained from an experimental pilot column operated at 2( BV )

/

/ hr. Other data

concerning the pilot column are: mass of carbon = 4.13 kg, water flowrate = 15 L / hr,

m 3 . Using the scale-up approach, determine the
values of the following parameters for the design column:
(a) Bed volume ( BV )
(b) Mass of carbon required ( M )

and packed carbon density = 400 kg /