Retardation factor of chlorobenzene and 1,3,5-trichlorobenzene

Calculate the retardation factor, R_{f i} , of chlorobenzene and 1,3,5-trichlorobenzene (1,3,5-TCB) in an aquifer at 10°C. (Note that the retardation factor is identical to the inverse fraction of compound in the mobile phase R_{f i} =f_iw^-1 if sorption equilibrium is attained; see Box 13 in the textbook).

Assume that retardation is determined by absorption to the aquifer solids' POM. The average organic carbon content of the aquifer material is 1.1 % (f_oc = 0.011). The minerals can be assumed to have a density of 2.5 kg L^-1 and the porosity is 0.33. Sorption coefficents at 10°C:

a) chlorobenzene: K_ioc =160 L kg_oc^-1

b) 1,3,5-TCB: K_ioc =1780 L kg_oc^-1

Answer:

a) 10

b) 100

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