Use of general purpose adsorption isotherms for heavy metal clay mineral interactions

Altin O., Ozbelge H., Dogu T.

JOURNAL OF COLLOID AND INTERFACE SCIENCE, cilt.198, sa.1, ss.130-140, 1998 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 198 Sayı: 1
  • Basım Tarihi: 1998
  • Doi Numarası: 10.1006/jcis.1997.5246
  • Dergi Adı: JOURNAL OF COLLOID AND INTERFACE SCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.130-140
  • Anahtar Kelimeler: adsorption isotherms, heavy metals, clay minerals, ION-EXCHANGE REACTIONS, LANGMUIR EQUATION, LEAD ADSORPTION, APPROXIMATIONS, DERIVATION, SURFACES, SOILS
  • Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

General purpose adsorption isotherm equations were fitted to the sorption data of lead and cadmium on both unmodified and Ca-saturated kaolinite and montmorillonite. Langmuir-Freundlich, Redlich-Petersen, Toth, Dubinin-Radushkevich, competitive Langmuir, and some modified forms of these isotherms were fitted to experimental data, and their goodnesses of fit are compared. The adjustable parameters of the Langmuir-and Freundlich-based isotherms were estimated by nonlinear least-squares analysis. The application of these two isotherms which allow for the effect of surface heterogeneity for both multiple and single desorbing ions during the sorption process was also studied. It was concluded that Redlich-Petersen, Toth, and original and modified forms of Dubinin-Radushkevich isotherms perform superior to the others both in high and lour concentration regions for both unmodified and Ca-saturated clays. Competitive Langmuir adsorption isotherm for Ca-saturated clays fitted web for Pb adsorption, while a change of slope was observed for Cd adsorption. (C) 1998 Academic Press.