Hexadecyl Trimethyl Ammonium Bromide-Modified Montmorillonite as a Low-Cost Sorbent for the Removal of Methyl Red from Liquid-Medium

In this study, montmorillonite (MMT) modified with a cationic surfactant (Hexadecyl trimethyl ammonium bromide, (HDTMA)) was used for the removal of methyl red (MR) from aqueous solution. The effect of different parameters like surfactant loading rate, contact time, pH, adsorbent dosage and initial MR content was investigated on the sorption. The sorption capacity was increased by increasing the surfactants loading rate up to 120% cation exchange capacity (CEC) of the MMT. The optimum uptake capacity of the sorbent (84.28 mg/g) was achieved within 30 min at pH of 6. The experimental data of the sorption was well fitted by pseudo-second-order kinetic and Freundlich isotherm models. The results showed that the HDTMA-MMT can be applied as an effective and inexpensive sorbent for the removal of MR from aqueous solution.