Question

Toluene has contaminated a city's drinking water supply. An activated carbon system will be designed to remove toluene to below regulatory levels. If equilibrium is achieved between activated carbon and aqueous-phases and the concentration of toluene in the aqueous-phase is 0.010 mg/L, what will be the concentration of toluene sorbed to the activated carbon? The Freundlich parameters for toluene and the particular type of activated carbon are: K= 159 mg/g (L/mg)^1/n = 0.54. Express your answer in units of mg toluene per kg activated carbon.

Answer 1

We have:

K = 159 mg/g

1/n = 0.54

The concentration of toluene sorbed on activated carbon can be calculated using the Freundlich equation which is given as:

where

x = mass of adsorbate

m = mass of adsorbent

c = Equilibrium concentration of adsorbate in solution.

K and n are constants for a given adsorbate and adsorbent at a particular temperature.

Substitutin the values provided into the Freundlich equation, we get:

x/m = 159 X (0.01)^-0.54

x/m = 1911.6 mg/g

= 1911.6 X 1000

= (1.9116 X 10⁶) mg/kg

Hence, the concentration of toluene sorbed to the activated carbon is (1.9116 X 10⁶) mg of touluene per kg of activated carbon.