Characterization and 2,4-D adsorption of sepiolite nanofibers modified by N-cetylpyridinium cations

In this study, a novel N-cetylpyridinium (NCP)-modified sepiolite with the potential for the removal of organic contaminants from aqueous media was synthesized and the adsorptive removal of 2,4-D (2,4-Dichlorophenoxy acetic acid) herbicide by the natural and NCP-modified sepiolites was investigated. Maximum adsorption capacity of sepiolite for NCP surfactant was 240 mmol/kg, that is so much higher than the clay CEC. Fourier transformed infrared (FT-IR) spectroscopic studies revealed changes of sepiolite surface properties when this mineral was loaded with NCP, equal to the maximum adsorption capacity of the clay; however, X-ray diffraction (XRD) analysis and Scanning Electron Microscopy (SEM) showed almost no structural or morphological changes after NCP adsorption. The clay surface modification significantly improved 2,4-D removal from water. Sepiolite adsorption capacity for 2,4-D was increased with enhancing the surfactant loading, which was exceeded to the clay CEC. Therefore, the NCP-sepiolite could be efficiently applied for eliminating 2,4-D from polluted waters.

Figure optionsDownload as PowerPoint slideHighlights
► We used Na- and NCP-sepiolite to remove 2,4-D from aqueous solution.
► Na-sepiolite did not adsorbed 2,4-D herbicide from solution.
► Surfactant modified sepiolites showed a good 2,4-D adsorption capacity.
► 2,4-D removal by the organo-clays increased as surfactant loading raised.