Enhanced removal of p-nitrophenol from aqueous media by montmorillonite clay modified with a cationic surfactant.

•Montmorillonite was modified with cetyltrimethylammonium bromide.•The modification was confirmed by FTIR, TG/DTA, XRD, SEM/EDX, specific surface area, and zeta potential measurements.•The kinetics of adsorption were described by a pseudo-second order model.•The thermodynamic parameters showed a non-spontaneous, exothermic process.•MCCTA has potential use as an adsorbent of p-nitrophenol from aqueous media.