Surfactant-supported organoclay for removal of anionic food dyes in batch and column modes: adsorption characteristics and mechanism study

Abstract This study aimed to create CTAB-modified bentonite organoclay (Bt@CTAB) by mixing the naturally occurring mineral (Bt) with cationic surfactant cetyltrimethylammonium bromide (CTAB). Elemental analysis, N 2 adsorption–desorption isotherm, scanning electron microscopy (SEM), FTIR spectroscopy, XRD, and thermogravimetric (TGA) analysis have been employed analyze both unmodified Bt Bt@CTAB organoclay. The dye sorption onto was investigated in batch column modes using aqueous solutions of anionic food dyes, viz ., Sunset yellow FCF (E110), Azorubine (E122), Ponceau 4R (E124) (individually or a mixture). Experimental variables affecting adsorption process, such as initial concentration, contact time, temperature, pH, adsorbent dose, are evaluated. From kinetic investigations, E110, E122, E124 dyes well matched pseudo-second-order model. E110 E122 attained equilibrium 120 min while 240 for E124. were expected achieve maximum efficiencies at concentration 100 ppm (E110 E124) 150 (E124), an dosage 0.4 gL −1 , pH 5. In addition, Langmuir model best fits isotherm data, capacity 303 K being 238 mg/g, 248.75 358.25 mg/g E124, respectively. can be regenerated up 4th cycle successfully. thermodynamic studies revealed spontaneous exothermic nature these prepared successfully applied removal from real water samples, synthetic effluents, colored soft drinks recovery ( R %) higher than 95%. plausible mechanism is proposed due electrostatic interaction hydrogen bond formation. Finally, present shows that may efficiently effectively remove wide range drinks.