Affinity of clinoptilolite-based zeolites towards removal of Cd from aqueous solutions

Gedık K., İmamoğlu İ.

SEPARATION SCIENCE AND TECHNOLOGY, vol.43, pp.1191-1207, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 43
  • Publication Date: 2008
  • Doi Number: 10.1080/01496390801888060
  • Journal Name: SEPARATION SCIENCE AND TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1191-1207
  • Keywords: pretreatment, isotherm modeling, ion exchange, adsorption, exchangeable cations, HEAVY-METALS, NATURAL ZEOLITE, ION-EXCHANGE, ADSORPTION-ISOTHERMS, WASTE-WATER, CADMIUM, COPPER, PB2+, LEAD, SODIUM
  • Middle East Technical University Affiliated: Yes

Abstract

Cd removal from aqueous solutions using as-received and pretreated forms of two different clinoptilolite samples (denoted GC and BC) was investigated and dissimilar sorption affinities were revealed. Equilibrium behavior of systems were modeled using six different adsorption isotherms. The maximum sorption capacities, as obtained from the solubility-normalized Dubinin-Astakhov model for as-received samples, were determined as 0.18meq/g and 0.12meq/g for GC and BC, whereas 0.72meq/g and 0.41meq Cd/g was determined for their pretreated forms, respectively. Examination of the release of exchangeable cations into the solution at equilibrium and the change of pH were discussed in terms of varying prevalence of ion exchange, dissolution of the sorbent and adsorption.