title: Continuous elimination of Pb2+, Cu2+, Zn2+, H+ and NH4 + from acidic waters by ionic exchange on natural zeolites.
abstract: A study of breakthrough curves for cations usually found in acid mine drainage (Pb(2+), Cu(2+), Zn(2+) and H(+)) and municipal wastewater (NH(4)(+)) have been conducted on some natural zeolitic tuffs. The zeolitic tuffs used in this study are: three zeolitic tuffs from Cayo Formation, Guayaquil (Ecuador), characterized by X-ray diffraction as clinoptilolite (sample CLI-1) and heulandite (samples HEU-1 and HEU-2)-rich tuffs, and two zeolitic tuffs from Parnaiba Basin, Belem do Pará (Brazil), characterized as stilbite-rich tuffs (samples STI-1 and STI-2). The clinoptilolite sample CLI-1 shows an exceedingly good exchange capacities for Pb(2+) and NH(4)(+) as received, and also a very high exchange capacity for Cu(2+) and Zn(2+) when conditioned with 2M sodium chloride, with much higher values than those reported in the literature for other clinioptilolite ores. A general order of effective cation exchange capacity could be inferred from breakthrough curves on these zeolitic tuffs: CLI-1 > HEU-2 > HEU-1 > STI-2. Since it is true for most of the cations studied.
authors.affiliation: ETS Ingenieros de Minas, Universidad Politécnica de Madrid, Rios Rosas 21, 28003 Madrid, Spain.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Calvo
authors.forename: Laureano
authors.initials: L
authors.lastname: Canoira
authors.forename: Fernando
authors.initials: F
authors.lastname: Morante
authors.forename: José M
authors.initials: JM
authors.lastname: Martínez-Bedia
authors.forename: Carlos
authors.initials: C
authors.lastname: Vinagre
authors.forename: Jerónimo-Emilio
authors.initials: JE
authors.lastname: García-González
authors.forename: Jan
authors.initials: J
authors.lastname: Elsen
authors.forename: Ramon
authors.initials: R
authors.lastname: Alcantara
mesh_terms: D000143:Acids; D007474:Ion Exchange; D007477:Ions; D008670:Metals / Q000302:isolation & purification*; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods; D017641:Zeolites / Q000737:chemistry*
chemical_list: D000143:Acids; D007477:Ions; D008670:Metals; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; C083175:clinoptilolite; D017641:Zeolites