Telon dye removal from Cu(II)-containing aqueous media using p-diphosphonium organo-montmorillonite

Abstract

Ion-exchange of montmorillonite with para-bis(triphenyl phosphonium methylene)-benzene ions (p-TPhPMB) provided an organo-montmorillonite adsorbent with improved affinity towards Telon dyes. Adsorption tests applied to Telon-red and Telon-blue in the presence of Cu(II) cations revealed a significant increase in the maximum adsorption capacity from ca. 11-26 for the starting clay mineral to ca. 110-160 mg.g-1 after intercalation. This improvement was attributed to increases in both the organophilic character towards the organic dyestuffs investigated and the interlayers spacing. Besides dye-diphosphonium and Cu(II)-diphosphonium interactions, dye adsorption on organo-montmorillonite also involved the formation of Cu(II) exchanged Telon-dye species. It was found that dye adsorption involves not only binary interactions between the three chemical species, but also synergy due to a possible bridging action of the divalent Cu(II) cations. On organo-Mt, the organophilic character was a key factor for higher amounts of adsorbed dye.

Synthesis of bisimidazolium–ionic liquids: Characterization, thermal stability and application to bentonite intercalation

“…The chemical composition of purified bentonite was found to be as follows: 64.7% SiO 2 , 18.1% Al 2 O 3 , 0.95% Fe 2 O 3 , 2.66% MgO, 0.8% K 2 O, 0.61% CaO, 0.2% TiO 2 , 1.43% Na 2 O, 0.05% As, and 10.0% loss on ignition [16][17][18][19].…”

“…The mineralogical analysis showed that the native crude clay mineral predominantly contains montmorillonite (86 wt.%). The clay composition also contains quartz (10%), cristoballite (3.0%) and beidellite (less than 1%) [18,19].…”