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328 4. Adsorption and Ion Exchange

,
2001; Zulfadhly et al ., 2001; K o et al ., 2000, 2002; Sag and 2001), dyes adsorption Actay
v
using metal hydroxide and actiated carbon (Netpradit et al ., 2004; W and er alk
Weatherley, 1997; K o et al ., 2002), and phenol biosorption using biomass (Rao and
Viraraghavan, 2002).

Wheeler–Jonas model f OCs adsor ption or V The Wheeler–Jonas equation is used for
adsorption of VOCs using carbons. This equation is of the same form of the Thomas model
with some modif ications:

qM e q C  o C br 
eb
t br ln   (4.187)
CQ o kC v o  C br 
where:
t br the time to reach the breakthrough concentration ( C br )
k v the oerall adsorption rate coef time icient, f v –1
q e the equilibrium adsorption capacity of the carbon for a gi . en v v apor
e The Dubinin–Raduskvish isotherm (DR) can be used for the determination of q eq .
v The oerall adsorption rate coeficient can be estimated using the following equations. f
Jonas and Rehrmann (1974) proposed a model deried for 1% breakthrough fraction: v

k 111.6 u d s 0.5 1.5 (4.188)

p
where u s is the superficial velocity in cm/s and d p is the particle diameter in cm.
v
Lodewyckx and Vansant (2000) proposed a model deried for 0.1% breakthrough
fraction:

48 0.33 u 0.75
k s (4.189)

d 1.5 p

Wood and Stampfer (1993) proposed the follo wing correlation:

   C  C    1
   0.063 0.0058ln   o br   

k   1   0.027 0.000825    C br     (4.190)

 u  s   P e  
 
     

where the superficial velocity is in cm/s, concentration in ppm, and P is the molar polar-
e
ization of the adsorbate in cm 3 /mol.