Turkish Journal of Chemistry, Vol.27, No.4, 477-486, 2003
Synthesis, characterization and applications of sol-gel derived zirconium oxide adsorbent powder: Removal from aqueous solution of phenol and p-chlorophenol
Adsorbent powders were prepared from the uncatalysed hydrolysis-condensation reactions of different complexes that were synthesized by the reactions of Zr(OPrn)(4) with different chelating ligands (such as allylacetic acid [AAH], vinylacetic acid [VAH] and citraconic acid [CAH]). The complex products were characterized by FT-IR, H-1-NMR and C-13-NMR spectra. The maximum combination ratios of AAH/Zr(OPrn)(4), VAH/Zr(OPrn)(4) and CAH/Zr(OPrn)(4) were 1.7, 0.9 and 1.3, respectively. The hydrolysis-condensation products of these complexes were calcinated at 900 degreesC and half of them were coated with 3-glycidyloxypropyltrimethoxysilane (GLYMO). The surface area and average pore diameter of the powders were estimated by the analysis of adsorption/desorption BET isotherm data. The adsorption capacities of these powders for aqueous phenol and p-chlorophenol were calculated following spectrophotometric determination. Phenol and p-chlorophenol adsorption on all of the GLYMO-coated adsorbents were satisfactory, e.g., the adsorbent obtained from the hydrolyzed, calcinated and GLYMO-coated form of Zr(OPrn)(2.3)(AA)(1.7) adsorbed 63% of phenol while the uncoated form adsorbed only 10%. The adsorption isotherm has been determined and data have been analyzed according to the Freundlich model.