Adsorption of Malachite Green with Sodium Dodecylbenzene Sulfonate Modified Sepiolite: Characterization, Adsorption Performance and Regeneration

Abstract

The adsorption of malachite green (MG) onto sodium dodecylbenzene sulfonate (SDBS)-modified sepiolite was investigated with respect to pH, oscillation rate, MG dosage and adsorbent dosage. The modification condition and modified sepiolite characterization were examined. The conditions of 100% cation exchange capacity (CEC), pH value of 9, contact time of 60 min and 25 °C were deemed as the optimal conditions. The interlayer spacing of sepiolite was expanded and the surface hydrophobicity improved due to the entering of SDBS into the interlayer structure of the sepiolite ore. This is probably the reason for its adsorption enhancement. The adsorption of malachite green by organic sepiolite is in line with the quasi-secondary kinetic model. The results from the regeneration procedure suggest that a superior regeneration property obtained with 0.2 mol/L HCl concentration.

Adsorption of Mixed Dye System with Cetyltrimethylammonium Bromide Modified Sepiolite: Characterization, Performance, Kinetics and Thermodynamics

“…Figure 2a shows that the characteristic dispersion peak of sepiolite at 2θ value of 9.4/9.44 was significantly strengthened after CTMAB modification and no significant changes occurred at other characteristic peak positions. On the other hand, the diffraction peak of the quartz also enhanced after the surfactant modification, which was different with previous report [34]. The d 001 value of modified sepiolite was slightly increased to 0.9365 nm, which indicate that the CTMAB intercalated into the sepiolite.…”

“…An X-ray diffraction spectrometer (D8-Advance, Burke, Germany) was employed for X-ray diffraction spectroscopy (XRD) test [33]. The tube pressure was 20 KV, the scanning range was 5-60 • and the scanning speed was 0.02 • /0.2 s [34]. A Fourier-transform infrared spectrometer (Spectrum One B, Perkin Elmer, USA) was used to detect the Fourier-transform infrared spectroscopy (FT-IR) [33].…”

Adsorption of Acid Orange Ⅱ with Two Step Modified Sepiolite: Optimization, Adsorption Performance, Kinetics, Thermodynamics and Regeneration

“…The functional modification of CTAB mainly occurrs on the surface of the raw sepiolite, thereby maintaining the original sepiolite structure. This is also in accordance with previous research [2,17]. Figure 1a, the 100% CEC CTAB-modified sepiolite was utilized; In Figure 1b, the modified sepiolite after 200 °C heat modification process was utilized.…”

“…A dye is an organic compound which stains the substance in an aqueous solution or other medium. The dyestuff is employed with a dispersed state or dissolved in a water solvent to form a solution to dye the material [1,2]. Acid Orange II is a commonly used acidic water-soluble dye and has strong carcinogenicity [3].…”

“…Cetyltrimethylammonium bromide (CTAB) was widely reported in adsorber (e.g., zeolite, bentonite and montmorillonite) modification [28][29][30]. On the other hand, surfactant modification was proven as an efficient method to enhance the adsorption performance of sepiolite [2].…”