Gemini Quaternary Ammonium Surfactants with Different Counterions-modified Montmorillonite for Efficient Removal of Methyl Orange.

Abstract: Organic Na-montmorillonite (OMt-12-2-12·2Y^–, Y=CH₃CO₃ ^– , C₆H₅COO^– and Br^– ) modified by a series of Gemini quaternary ammonium surfactants with different counterions was prepared for enhancing the adsorption capacity of methyl orange. Compared with the initial adsorption capacity of 5.251 mg/g of Na-Mt, the adsorption effect of OMts under the optimal conditions increased by about 31~34 times. The adsorption isotherms and kinetics of all adsorption processes were respectively described by Langmuir and pseudo-second-order models. The structure, hydrophobicity and hydration of the counterions, as well as the affinity of the counterions with the long aliphatic chains, had a certain influence on the adsorption performance of OMts for methyl orange. [ABSTRACT FROM AUTHOR]