Insights into tetracycline adsorption onto kaolinite and montmorillonite: experiments and modeling

  • Zhao Y
  • Gu X
  • Li S
 et al. 
  • 8

    Readers

    Mendeley users who have this article in their library.
  • 12

    Citations

    Citations of this article.

Abstract

Adsorption of tetracycline (TC) on kaolinite and montmorillonite was investigated using batch adsorption ex- periments with different pH, ionic strength, and surface cov- erage. As a result, pHand ionic strength-dependent adsorption of TC was observed for the two clay minerals. The adsorption of TC decreased with the increase of pH and ionic strength, and high initial TC concentration had high adsorption. In ad- dition, a triple-layer model was used to predict the adsorption and surface speciation of TC on the two minerals. As a result, four complex species on kaolinite (≡X− H3TC+, ≡X− H2TC±, ≡SOH0 H2TC±,and ≡SOH0 HTC−) and three species on montmorillonite (≡X− H3TC+, ≡X− H2TC±,and ≡SOH0 HTC−) were structurally constrained by spectroscopy, and these species were also successfully fitted to the adsorp- tion edges of TC. Three functional groups of TC were in- volved in these adsorption reactions, including the positively charged dimethylamino group, the C=O amide I group, and the C=O group at the C ring. Combining adsorption experi- ments and model in this study, the adsorption of TC on kao- linite and montmorillonite was mainly attributed to cation ex- change on the surface sites (≡X−) compared to surface com- plexation on the edge sites (≡SOH) at natural soil pH condi- tion. Moreover, the surface adsorption species, the corre- sponding adsorption modes, and the binding constants for the surface reactions were also estimated

Author-supplied keywords

  • Adsorption
  • Kaolinite
  • Montmorillonite
  • Surface complexation model
  • Tetracycline

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free