Zeolitic volcanic tuffs from Măcicaş (Cluj County), natural raw materials used for NH4+ removal from wastewaters

Abstract

ABSTRACT. Volcanic tuffs out cropping in Măcicaş area (Cluj County) have been investigated and tested for their ammonium removal capacity. The zeolitic volcanic tuffs from Măcicaş are mainly represented by vitric and vitric crystal tuffs. In this region, significant amounts of volcanic glass in the pyroclastic sequence have been replaced by zeolites (between 50-80 %). The main zeolite species identified in volcanic tuffs from Măcicaş is clinoptilolite and subordinately mordenite. The zeolitic tuff samples considered in zeolitic sodium form (labeled M1-Na and M2-Na) are tested in ammonium removal experiments. The ammonium ions were completely removed from 0.0716g/dm 3 NH 4 + solution onto 10g of zeolitic material in static regime. In dynamic regime, the ammonium ions were completely removed after 250 ml and 500 ml solution passed on M1-Na and M2-Na sample respectively. Also the zeolite exhaustion takes place after more than 1500 ml solution is processed in both cases. The ionic exchange properties suggest that the zeolitic tuff of the Măcicaş region can be used as a final stage (following the biological process) in wastewater treatment plants in order to assure compliance with environmental standards.

Adsorption of Hg2+, Cu2+ and Zn2+ ions from aqueous solution using formaldehyde cross-linked modified chitosan–thioglyceraldehyde Schiff's base

“…However, the benefits of this technique are offset by the rising cost of adsorbents like activated carbon and synthetic ion exchangers. The hunt for a cheap and widely available adsorbent has motivated researchers to focus on naturally available adsorbents [6][7][8][9].…”

Evaluation of Cu2+, Co2+ and Ni2+ ions removal from aqueous solution using a novel chitosan/clinoptilolite composite: Kinetics and isotherms

“…These values were estimated according to the methods presented elsewhere [19]. The natural CPL sample used in the preparation of the composite comes from volcanic tuffs containing 60-70% CPL, cropped out in Mȃcicaş area (Cluj County, Romania), and has the following elemental composition: (NaKCa 0.5 ) 5.4 (Al 5.4 Si 30.6 O 72 )·20H 2 O (Si/Al = 5.7) [7]. The zeolitic volcanic tuff was used as collected.…”

“…However, the benefits of this technique are offset by the rising cost of adsorbents like activated carbon and synthetic ion exchangers. The hunt for a cheap and widely available adsorbent has motivated researchers to focus on naturally available adsorbents like natural zeolites [5][6][7][8]. Clinoptilolite (CPL), one of the most common natural zeolites, is a hydrated alumina-silicate member of the heulandite group, occurring in the zeolitic volcanic tuffs, being widespread in many countries in the world.…”

“…Clinoptilolite (CPL), one of the most common natural zeolites, is a hydrated alumina-silicate member of the heulandite group, occurring in the zeolitic volcanic tuffs, being widespread in many countries in the world. CPL is characterized by infinite three-dimensional frameworks of [AlO 4 ] 5− and [SiO 4 ] 4− tetrahedra linked to each other by sharing all of the oxygens, and the negative charge being balanced by metal cations, like Na + , K + , Ca 2+ and Mg 2+ [7].…”

Investigations on some zeolitic volcanic tuffs from Cluj County (Romania), used for zinc ions removal from aqueous solution

“…For example, clinoptilolite, which is the most abundant natural zeolite (Italy, Croatia, Turkey, Greece, and Romania) was shown to be an efficiently remover of NH (Ouki and Kavannagh, 1997;Langella et al, 2000;Cincotti et al, 2001;Badillo-Almaraz et al, 2003;Panayotova and Velikov, 2003;Erdem et al, 2004;Peric et al, 2004;Top and Ulku, 2004;Bedelean et al, 2006;Stanca et al, 2006;Burcă et al, 2008). Clinoptilolite can also be used as an amendment to sewage sludge or soil in order to stabilize the heavy metal ions and to prevent their entering in the ecosystem by leaching (Zorpas et al, 2000a(Zorpas et al, , 2000b(Zorpas et al, , 2002Moirou et al, 2001).…”