Representative samples of zeolitic tuffs from Măcicaş, Aluniş and Apahida occurrences (Cluj County, Romania) were investigated using optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and wet chemical analyses. The studied tuffs samples are mainly represented by vitric and vitric crystal varieties. The mineral assemblage suggests a rhyo-dacitic petrographic type of the volcanic tuff. Diagenetic alteration process in the pyroclastic sequence from this region led to the formation of zeolites, mainly clinoptilolite. The zeolitic tuffs under study can be used in wastewaters treatment to remove Zn2+ ions. Zn2+ removal was performed on some bulk samples: Aluniş (labelled A1), Apahida (Ap) and Măcicaş (M2) grain size of 0.2-0.4 mm. Each sample was chemically modified with HCl 1M (Z-H form) and NaCl + NaOH 1M pH = 10 (Z-Na form). The ionic exchange processes were realized in a batch reactor (immobile phases) and in a fixed bed column. Ionic exchange efficiencies for the samples considered are presented for static and dynamic regimes. Removal efficiencies higher than 53.97% and exchanged Zn2+ quantities higher than 1.05 mg/g were obtained. Therefore the zeolitic tuffs under study are considered to be active in the ionic exchange process. The results for all the samples considered in batch and fixed bed experiments are presented by means of cation exchange capacity, CEC and removal efficiency.
Bedelean, Horea; Maicaneanu, Andrada; Burca, Silvia; and Stanca, Maria
Investigations on some zeolitic volcanic tuffs from Cluj County (Romania), used for zinc ions removal from aqueous solution,
Studia UBB Geologia
Available at: http://scholarcommons.usf.edu/geologia/vol55/iss1/art2