Synthesis of C-4-Hydroxy-3-methoxyphenylcalix[4]resorcinarene and Its Application as Adsorbent for Lead(II), Copper(II) and Chromium(III)

This study aims to synthesize C-4-hydroxy-3-methoxyphenylcalix[4]resorcinarene and investigate the kinetics of its application as an adsorbent for lead(II), copper(II) and chromium(III) ions. The interaction between this adsorbent and these metal ions was also studied. In this work, C-4-hydroxy-3-methoxyphenylcalix[4]resocinarene was synthesized from vanillin and resorcinol as a light red solid in 84% yield, and its ability to adsorb the metal ions was conducted in a batch system. The kinetics and interaction of the adsorbent with these metal ions were analyzed by FAAS spectrometry and FT-IR respectively. The optimum pH values of this adsorbent to adsorb Pb(II), Cu(II) and Cr(III) ions were determined to be 5.48, 5.70 and 4.50 respectively. The adsorption rate order of these metal ions onto adsorbent was found to be Pb(II) > Cu(II) > Cr(III). The competitive adsorption of these heavy metal ions was also investigated. FT-IR spectra showed the presence of interaction between Pb(II) and the adsorbent, but no such interaction was observed between the adsorbent and Cr(III) or Cu(II). Further studies based on the 1H NMR and UV spectra of the free and metal ion loaded adsorbents confirmed the presence of interaction between the adsorbent and all metal cations.