| In this research,an efficient adsorbent was synthesized by successfully anchoringsodium dodecyl benzene sulfonate(SDBS) on sodium-modified sepiolite and whichwas then used to investigate the adsorption behavior of Pb(II) ions from aqueoussolutions. The effects of adsorbent dose, initial Pb(II) concentration,pH, contact time,ionic strength and temperature on the adsorption were investigated. In addition，thekinetic and thermodynamic properties of the Pb(II) adsorbed on SDBS-Na-sepiolite，the mechanism were also investigated．The scanning electron microscope and the fourier transform-infared spectroscopyanalysis showed that SDBS has been introduced onto the surface of sepiolite.According to X-Ray diffraction analysis,the sepiolite crystal layer spacing becomedbigger as the result of treatment and after pured the sepiolite had lessimpurities.Surface area analysis showed that the special surface area ofSDBS-Na-sepiolite was30.14m2/g which was lower than48.58m2/g of sepiolite.Adsorption of Pb(II) on SDBS-Na-sepiolite were performed by batchexperiments under different conditions. Significantly improving adsorptive removalefficiency of Pb(II) were observed with the exaltation of pH, increase of adsorbentdosage and temperature. The higher the concentration of NaCl，KNO3，NaNO3andKCl， the greater impact on the removal efficiency.In the rate of200rad/min,pH is5.0,dosage of organic sepiolite is1g/L,the equilibrium adsorption capacity achieves172.93mg/g at298K.The adsorption of Pb(II) by SDBS-Na-sepiolite satisfied pseudo second ordermode and the Langmuir isotherm equation. H0=89.38KJ/mol, S0=0.3735KJ mol-1K-1,G00,that meaned the whole adsorption process was spontaneous endothermicreaction. The activation energy was20.005kJ/mol which could primarily prove thatthe adsorption of Pb(II) on it was chemical adsorption．... |
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