1070-4272/04/7702-0222 C 2004 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 77, No. 2, 2004, pp. 222!225. Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 2, 2004,
Original Russian Text Copyright + 2004 by Kolosnitsyn, Yapryntseva.
AND CORROSION PROTECTION OF METALS
Cathodic Deposition of Zinc from Dilute Solutions
onto a Rotating Disc Electrode
V. S. Kolosnitsyn and O. A. Yapryntseva
Institute of Organic Chemistry, Ufa Scientific Center, Russian
Academy of Sciences, Ufa, Bashkortostan, Russia
Received May 22, 2003
Abstract-The cathodic deposition of zinc onto a rotating disc electrode was studied. The influence exerted
by various parameters on the process was examined. The observed phenomena were explained in terms of
corrosion and the positive difference-effect.
Purification of sewage to remove heavy-metal ions
is a problem of current importance for many industries.
Various methods can be used for sewage purification,
but electrochemical methods, such as electrocoagula-
tion, electroflotation, electrodestruction, and electro-
deposition of metals, are of particular interest. The
electric treatment makes it possible to purify wastewa-
ter of varied composition and dispersity without rais-
ing the content of salts in a water being purified and,
rather frequently, with precipitates not formed at all
or formed in a considerably decreased amount .
Among the electrochemical methods mentioned above,
the electrolysis is of special interest, since it can be
performed without use of chemicals in the course of
purification and yields a metal in the form of a target
product, which simplifies its further processing.
The electrodeposition of metals from dilute solu-
tions has its own specific features, which consist in
that the process rate is limited by delivery of a re-
agent to the electrode surface. This problem can be
solved by using a rotating disc electrode instead of
an immobile electrode. As shown previously , us-
ing a rotating disc cathode allows the rate of copper
electrodeposition from dilute solutions to be increased
by a factor of 5310, with a high current efficiency
In this study, we continue to examine the electro-
deposition of metals onto a rotating disc electrode and
the cathodic deposition of zinc from solutions with
concentrations of up to 1 g l
Zinc was electrodeposited in a glass cell with a ro-
tating cathode. The cell volume was 0.5 l. As cath-
odes were used discs made of stainless steel, sheet
copper, and aluminum. The cathode area was 160 cm
Semi-discs made of titanium gauze coated with ru-
thenium(IV) oxide served as anodes. Prior to the ex-
periments, the cathodes were trimmed with an emery
paper and washed in the electrolyte solution.
The electrodes were polarized in the galvanostatic
mode with a B5-49 source of stabilized current and
voltage. The voltage was monitored with a V7-27 A/1
The rate of rotation of the disc electrode was de-
termined and controlled using a tachometer.
Fig. 1. Effect of the rotation rate w on the current effi-
ciency CE by zinc in cathodic deposition from dilute so-
lutions. Supporting electrolyte 0.5 M Na
100 mg l
, pH 6, copper cathode.