Diphosphonium ion-exchanged montmorillonite for Telon dye removal from aqueous media

► Montmorillonite intercalation by diphosphonium ions promotes Telon dye adsorption. ► Acidic pHs favor dye adsorption, but induce also slight dealumination. ► Dealumination enhances dye adsorption by generating new terminal [MtOH2]+ sites. ► Telon-orange adsorbs ca. two times faster than Blue and Red Telon-dyes. ► Telon dye adsorption is an exothermal adsorption.