Anionic polyacrylamide as a substance strengthening the Pb(II) immobilization on the kaolinite surface

Abstract

Abstract: The main purpose of the study was to examine lead(II) ion immobilization on the kaolinite surface and determine the effect of soil flocculant (macromolecular compound) on this process. For this reason, the adsorption measurements of anionic polyacrylamide and/or Pb(II) ions on the kaolinite surface were performed. Moreover, the impact of heavy metal on electrokinetic and stability properties of kaolinite/polyacrylamide/supporting electrolyte system was determined. It was done based on the results of potentiometric titration, electrophoretic mobility, and absorbance measurements. The most important conclusions of the study were as follows: (1) kaolinite is an effective Pb(II) adsorbent when ion concentration in the environment equals 1 or 10 ppm (it adsorbs 80% and 72% of the ions, respectively), (2) when Pb(II) concentration in the environment is 100 ppm, kaolinite adsorbs only 29% of the ions, and (3) anionic polyacrylamide may strengthen the Pb(II) adsorption on the kaolinite surface (in the presence of 100 ppm AN PAM 30% and 1 ppm Pb(II), even 96% of the ions are adsorbed). Due to the above process, the bioavailability of heavy metal for organisms is considerably limited. Graphic Abstract: [Figure not available: see fulltext.].