Cationic surfactant modified NaY zeolite: Preparation, investigating the effect of surfactant concentration, and application for methyl orange adsorption from aqueous solution

Surfactant-modified zeolites (SMZs) are regarded as low-cost and effective adsorbents that have the capability to remove multiple classes of contaminants, including dyes. In the present study, faujasite type NaY zeolite was modified with different concentrations of CTAB cationic surfactant to investigate how CTAB concentration in terms of CMC affects the CTAB loading onto the surface of NaY zeolite and the structure of resulted coverage. Analyses of FTIR, zeta potential , contact angle, TGA/DTG, FE-SEM, and EDS were conducted to determine the characteristics of NaY and CTAB-modified zeolites and identify the resulted coverages. The performance of NaY and CTAB-modified zeolites for the elimination of methyl orange (MO) dye from aqueous solution was compared, and modified NaY with CTAB solution with a concentration of 1CMC (SMY-1CMC) was selected as the most efficient adsorbent. The influence of adsorbent dosage, contact time, initial pH, MO initial concentration, and co-existing ions on the MO removal efficiency was investigated. Hydrogen bond formation, electrostatic interaction , hydrophobic interaction, and cation-π interaction were identified to participate in the MO adsorption onto the surface of SMY-1CMC. According to the kinetic and equilibrium studies, the Elovich kinetic model and Sips isotherm demonstrated the best correlation with experimental data, suggesting the chemisorption of MO onto the heterogeneous surface of the adsorbent. The maximum adsorption capacity was determined to be 94.3755 mg/g based on the Sips isotherm. Based on the thermodynamic study, the MO adsorption process was exothermic and spontaneous. Eventually, SMY-1CMC exhibited a high potential for the removal of dyes from polluted water. • The effect of CTAB concentration (in terms of CMC) on the structure of the coverage formed on the NaY surface was investigated. • The final CTAB-modified zeolite demonstrated an acceptable adsorption capacity for methyl orange dye (94.3755 mg/g).