| The adsorption of acid fuchsin onto hexadecyltrimethylammoniumbromide(CTAB)-sepiolite was investigated in aqueous solution in a batch system withrespect to adsorbent dose, initial concentration, contact time, pH and temperature. Thesurface modification of CTAB-sepiolite was examined by the scanning electronmicroscope(SEM), Brunauer-Emmett-Teller (BET), X-ray diffraction(XRD) andfourier transform infared spectrometer(FTIR) technique.In addition，the kinetic andthermodynamic properties of the a cid fuchsin adsorbed on CTAB-sepiolite， themechanism were also investigated．The SEM and the FTIR analysis showed that CTAB has been introduced onto thesurface of sepiolite. According to X-ray diffraction analysis, the sepiolite crystal layerspacing was constant. SEM analysis showed that the special surface area ofCTAB-sepiolite was10.57m2/g which was lower than48.58m2/g of sepiolite.Adsorption of acid fuchsin on CTAB-sepiolite were performed by batchexperiments under different conditions. Significantly improving adsorptive removalefficiency of acid fuchsin were observed with the lower pH, temperature and increaseof adsorbent dosage. In the rate of180rad/min,pH is1.0, dosage of organic sepiolite is2g/L, the equilibrium adsorption capacity achieves83.68mg/g at298K.The adsorption of acid fuchsin by CTAB-sepiolite satisfied pseudo second ordermode and the Langmuir isotherm equation. H09.868KJ mol1,S07.62KJ mol1K1, G00, that meaned the whole adsorption process wasspontaneous exothermic process. The activation energy obtained in this study is+5.432kJmol-1indicating that the adsorption has a low potential barrier and assignedto a physisorption．... |
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