Applications of Chemical Kinetics in Environmental Systems - Elements of Environmental Engineering: Thermodynamics and Kinetics - page 325

[A]=0 [A]=0 [ A]=[A ] F

Unused
zone

Active
zone

Used
zone

G F ;[A] F

[A] F

[A]

Break point

t 2

t B

t 1

Time or volume of gas treated

FIGURE 6.33 Movement of the active (adsorption) zone through a fixed bed of activated
carbon. Breakthrough is said to occur when the adsorption zone has reached the exit of the
carbon bed.

over the entire column gives the following:

mass flow rate of pollutant into the adsorption zone = rate of adsorption.

M F
ρ g [

G F [ A ] F = A ] F = ρ ads A C V ads W 0 , (6.148)

where M F is the mass flow rate, ρ ads is the density of the

adsorbent, V ads is the adsorption zone velocity, A c is the cross-sectional area, and W 0

ρ g is the density of air,

d x

X 2

X 1

V g

V g

[ A ] + d[A]

V ads

[ A ]

G F
[A] F

G F
[A] = 0

Z s

δ

FIGURE 6.34 Analysis of an adsorption wave through a bed of activated carbon.