Effect of Hydrothermal Treatment on Structural Character of Palygorskite and Adsorption Efficiency for Methylene Blue

Abstract

Palygorskite is widely used as an adsorbent for all kinds of pollutants in wastewater. The effect of hydrothermal treatment parameters including temperature and time on palygorskite's structural character and its adsorption of methylene blue were studied. The structures of the prepared palygorskite adsorbent were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (IR), and Brunauer-Emmett-Teller (BET) analysis. The results illustrate that the palygorskite fibers become shorter evidenced by TEM analysis, but there is no obvious destruction of crystal structure in XRD patterns. The BET specific surface area of palygorskite gets the largest after hydrothermal treatment at 110 °C, and then gradually reduces. Correspondingly, the adsorption capacity of methylene blue (MB) on palygorskite increases at 110 °C and then decreases till 250 °C.