Study on adsorption and desorption properties of the starch grafted p-tert-butyl-calix[n]arene for butyl Rhodamine B solution

The adsorbents of starch grafted p-tert-butyl-calix[4,6,8]arene-SGCn (SGC4, SGC6, SGC8) are prepared. The products are characterized by FTIR, elemental analysis, thermal gravimetric analysis and scanning electron microscope. Static adsorption behavior is studied by using SGC8 as adsorbent, butyl Rhodamine B (BRB) solution as simulation dye wastewater. The adsorption of BRB onto SGC8 fits the second order kinetic model and the apparent adsorption rate constant is 0.002 g mg-1 min-1 at 25 deg. C. The equilibrium adsorption data are interpreted using Langmuir and Freundlich models. The adsorption of BRB onto SGC8 is better represented by the Langmuir equation. The thermodynamic parameters for the adsorption reaction are calculated through van't Hoff analysis. The adsorbent may be easily regenerated by using ethanol solution as desorption agent to extract dye from SGC8. The rate of desorption of BRB is dependent on the concentration of ethanol and the temperature. SGC8 exhibits excellent adsorption and desorption properties toward dye molecule. The new-style adsorbent of SGC8 is regarded as a potential adsorbent to deal with dye or organic wastewater.