Yu. O. Malkova, V. A. Brodskiy, V. A. Kolesnikov
Increase of lead (II) ions electroflotation
extraction efficiency from water solutions in the presence of ions of aluminium
(III) and iron(III) as a coagulant
Abstract
The research studied the effects of
solubility, disperse features (Z average diameter dav, and
charge (ζ-potential) of the particles of
heavy-metal slightly soluble compounds exemplified by aluminum (III),
iron(III), zinc(II) and plumbum(II) hydrates related to efficiency of their
removal from aqueous solutions in the composition by means of electroflotation
and filtration within a pH-range 5–12. High efficiency of
electroflotation-based Pb(II) removal from aqueous solutions is determined by
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 multi-component systems is
averaged compared to that of individual compounds. The maximum particle size of
the dispersed phase of multi-component systems comprising Al(III) and Pb(II)
hydroxides reaches 24 µm, Al(III), Zn(II) and Pb(II) hydroxides – 36 µm within
the pH 8,0, Fe(III), Zn (II) and Pb(II) hydroxides – 46 µm within the pH 9,0.
The same is true for averaging the electrokinetic potential which falls within
the range of –(2–9) mV for all studied systems within the pH range 7–9. The
research showed that the efficiency of removal of plumbum (II) and accompanying
metals compounds from wastewater through electroflotation reaches 90% to 97%
within the pH range 7.5–8.5. Further filtration of solutions allows to increase
removal to 99% and more.
Key words: electroflotation, aluminum(III),
iron (III), zinc(II), plumbum(II), electrokinetic potential, particle size,
removal efficiency.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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