Sorption of phenols from water in column systems using surfactant-modified montmorillonite

The sorption of phenol, m-nitrophenol (m-NP), and o-cresol from water onto montmorillonite modified with cetyltrimethylammonium bromide (CTAB) in a column was studied. The sorption isotherms were fitted by the Langmuir equation. Column experiments were performed at 25°C to determine the breakthrough curves at different flow rates, feed sorbate concentrations, and bed lengths. It was shown that the proposed constant-pattern wave approach with the Langmuir model could well describe the breakthrough curves. The time required when the effluent concentration reached half of the feed concentration (t_1/2) decreased with increasing feed flow rate, but the mass transfer coefficient (K_La) increased. In addition, an increase in feed sorbate concentration led to a decrease of both values of t_1/2 and K _La. The effect of axial dispersion on breakthrough dynamics in these sorption systems was finally discussed.