Uklanjanje CrO4 aniona iz vode prirodnim i modificiranim zeolitom

master's thesis

• Author: Marko Keletić
• Mentor: Mirela Rožić (mentor)
• Committee member: Mirela Rožić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Graphic Arts; Zagreb
• Defense date and country: 2008-7-00, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Graphic Technology

Abstract

Ispitana je adsorpcija kromatnog aniona (CrO42-) na klinoptilolitom bogatom tufu modificiranog

s kvarternim surfaktantom heksadeciltrimetil amonijevim bromidom (HDTMA+Br-). Na negativno nabijenu površinu klinoptilolita, HDTMA+ kationi adsorbiraju se jakim Coulombovim

(ionskim) vezama. Dok je prvi sloj surfaktanta vezan kationskom izmjenom, drugi sloj je vezan hidrofobnim interakcijama i stabiliziran protuionima (Br- ioni). Promjena zeta potencijala od negativnog na pozitivni mijenja prirodu zeolita koji poprima svojstva anionskog

izmjenjivača.

U otopini koncentracije 19,02 mg CrO42-/l na uzorak organo-zeolita s dvoslojnom konfiguracijom

HDTMA+ iona, adsorbiralo se 1,44 mg CrO42-/g zeolita (75,5%), a u otopini koncentracije

107,8 mg CrO42-/l adsorbiralo se 2,74 mg CrO42-/g zeolita (25,4%). Na uzorcima na čijim je vanjskim površinama adsorbiran samo monosloj HDTMA+ kationa najvjerojatniji mehanizam adsorpcije kromatnih aniona je površinsko taloženje HDTMA-CrO42- kompleksa.

Abstract (english)

The chromium anion (CrO42-) adsorption behavior on modified clinoptilolite-rich tuff was investigated. Tuff was modified with the quaternary surfactant hexadecyltrimethyl ammonium

bromide (HDTMA+Br-).

Cations adsorb on negatively charged clinoptilolite surface by Coulomb (ionic) bonds. While the first surfactant layer is engaged in cation exchange, second layer is engaged in hydrophobic

interactions and stabilized by Br- ions. Changing zeta potential from negative to positive changes the nature of zeolite, which becomes an ion exchanger.

On organozeolite sample with two-layer configuration of HDTMA+ ions, 1,44 mg CrO42-/g of zeolite was adsorbed from the solution containing 19,02 mg CrO42-/l, which is 75,5%

2,74 mg CrO42-/g of zeolite (25,4%) was adsorbed from the solution containing 107,8 mg CrO42-/l (25,4%).

The most probable mechanism of adsorption for chromate ions for samples on which outer surface only HDTMA+ cation layer was adsorbed, is the surface sedimentation of HDTMA-CrO42- complex.

• Keywords: ekologija; voda; klinoptilolit; surfaktant
• Keywords (english): ecology; water; clinoptilolite; surfactant
• Language: croatian
• URN:NBN: urn:nbn:hr:216:981051
• Study programme: Title: Graphic technology; specializations in: Graphic technology, Design of graphic products; Course: Graphic technology; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra inženjer/inženjerka grafičke tehnologije (sveučilišni/a magistar/magistra inženjer/inženjerka grafičke tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2024-04-17 10:38:04