Nonionic organoclay: A ‘Swiss Army knife’ for the adsorption of organic micro-pollutants?

• Published in: Journal of colloid and interface science Vol. 437; pp. 71 - 79
• Main Authors: Guégan, Régis, Giovanela, Marcelo, Warmont, Fabienne, Motelica-Heino, Mikael
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-01-2015; Elsevier
• Subjects: Adsorbents; Adsorption; Aluminum Silicates - chemistry; Cationic; Clay minerals; Continental interfaces, environment; Derivatives; Fittings; Microscopy, Electron, Transmission; Nonionic; Nonionic surfactant; Organic Chemicals - chemistry; Organic pollutants; Organoclay; Paraquat; Sciences of the Universe; Spectroscopy, Fourier Transform Infrared; Surfactants; Water; X-Ray Diffraction; Water; Clay minerals; Organic pollutants; Adsorption; Nonionic surfactant; Organoclay
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2014.09.043

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•Organoclays with their hydrophobic behavior adsorb nonpolar water contaminant.•No paraquat, an organic cation herbicide, sorption onto cationic organoclay.•Dimethyl-phthalate is adsorbed on the whole untreated and modified layered sorbents.•C10E3Mt organoclay can adsorb nonpolar, organic cation, and polar micro-pollutants.•Nonionic organoclay appears as a convenient tool in environmental applications.
A Na exchanged montmorillonite (Mt) was used as a starting layered material for the preparation of two organoclays synthesized with benzyl decyltrimethyl ammonium (BDTA) cationic surfactant and the tri-ethylene glycol mono n-decyl ether(C10E3), a nonconventional nonionic surfactant. The adsorption of the surfactants was performed at an amount of 0.7 times the cation exchange capacity (CEC) for BDTA and below the critical micelle concentration (cmc) where C10E3 is in a monomer state, leading to the intercalation of a lateral monolayer surfactant arrangement within the interlayer space and about 5–7% organic carbon content in organoclays. The environmental properties of both nonionic (C10E3Mt) and cationic (BDTAMt) organoclays were compared to those of the starting Mt clay with the sorption of three micro-pollutants: benzene, dimethyl-phthalate and paraquat. The adsorption isotherms and the derivative data determined through the fitting procedure by using Langmuir, Freundlich and Dubinin–Radushkevitch equation models explicitly highlighted the importance of the chemical nature of the micropollutants, which play on the adsorbents efficiency. The adsorption data combined with FTIR and XRD supplementary results suggest that C10E3Mt nonionic organoclay, although being less efficient for the retention of the different micropollutants, turned out to be the most polyvalent adsorbent since such hybrid material could adsorb the entire studied organic compounds.