Increased Efficiency of Electroflotational Extraction of Lead(II) Ions from Water Solutions in the Presence of Ions of Aluminum(III) and Iron(III) as Coagulants

This article studies the effects of solubility, disperse features (average diameter d(av) and charge (zeta-potential)) of the particles of heavy-metal slightly soluble compounds exemplified by aluminum(III), iron(III), zinc(II), and lead(II) hydrates related to the efficiency of their removal from aqueous solutions in the composition by electroflotation and filtration within the pH range 5-12. The efficiency of the electroflotation-based Pb(II) removal from aqueous solutions is determined by the sorption of ions and the dispersed Pb(II) phase on the Al(III) and Zn(II) dispersed phase. The size of the disperse phase of multicomponent systems is averaged compared to that of individual compounds. The maximum particle size of the dispersed phase of multicomponent systems comprising Al(III)-Zn(II)-Pb(II) at a pH of 8.0 reaches 36 mu m, in the Fe(III)-Zn(II)-Pb(II) and this parameter reaches 46 mu m at a pH of 9.0. The zeta-potential of the dispersed phase of the studied systems varies in the range from -2 to -9 mV for all the systems within the pH range 7-9. The research showed that the efficiency of the removal of lead(II) and accompanying metals compounds from wastewater through electroflotation reaches 95-97% within the pH range 8-9. Filtration of the solutions allows us to improve the removal to 99% and higher.