title: Preparation and application of organo-modified zeolitic material in the removal of chromates and iodides.
abstract: The removal of chromates and iodides from aqueous solutions by organo-modified tuffs from the Pentolofos area (Thrace, Greece) was investigated using (51)Cr- and (131)I-labelled solutions and gamma-ray spectroscopy. The zeolitic material was modified by hexadecyltrimethyl-ammonium bromide (HDTMA-Br) and octadecyltrimethyl-ammonium bromide (ODTMA-Br) and characterized by scanning electron microscopy, FT-IR spectrometry and zeta potential measurements. Both experimental study and modelling indicated that both organo-zeolitic sorbents have a bigger affinity for iodide than for chromate. The chromium uptake did not seem to be influenced by the type of modifier but showed, as expected, a dependence on the solution pH. The maximum sorption capacity (2.27 mg/g) of Cr(VI) was achieved for the solution of initial pH 4. On the other hand, the HDTMA-modified tuff showed a lower sorption affinity for iodides than did the ODTMA-modified one (3.37 and 4.02 mg/g, respectively).
authors.affiliation: Department of Civil and Environmental Engineering, Rzeszów University of Technology, 6 Powstańców Warszawy Str., 35-959 Rzeszów, Poland. jwarchol@prz.rzeszow.pl
authors.forename: J
authors.initials: J
authors.lastname: Warchoł
authors.forename: P
authors.initials: P
authors.lastname: Misaelides
authors.forename: R
authors.initials: R
authors.lastname: Petrus
authors.forename: D
authors.initials: D
authors.lastname: Zamboulis
mesh_terms: D000327:Adsorption; D000838:Anions / Q000737:chemistry; D002840:Chromates / Q000737:chemistry* / Q000302:isolation & purification*; D007454:Iodides / Q000737:chemistry* / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning; D013055:Spectrophotometry, Infrared; D017641:Zeolites / Q000737:chemistry*
chemical_list: D000838:Anions; D002840:Chromates; D007454:Iodides; D017641:Zeolites