1070-4272/01/7410-1698 $25.00 C 2001 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 74, No. 10, 2001, pp. 1698!1701. Translated from Zhurnal Prikladnoi Khimii, Vol. 74, No. 10, 2001,
Original Russian Text Copyright + 2001 by Lupeiko, Gorbunova, Bayan.
OF CHEMISTRY AND TECHNOLOGY
Deep Purification of Aqueous Solutions
to Remove Chromium(III) with Industrial
T. G. Lupeiko, M. O. Gorbunova, and E. M. Bayan
Rostov State University, Rostov-on-Don, Russia
Received November 17, 2000; in final form, April 2001
Abstract-The possibility of diminishing chromium(III) ion concentration in aqueous solutions to a MPC
(maximum permissible concentration) level with the use of industrial carbonate-containing wastes was studied.
The influence exerted by the chromium(III) ion concentration in a starting solution, duration of sorbent
contact with the solution, anion composition of the solution, temperature, and other conditions on the degree
of recovery of Cr(III) ions and on the sorbent consumption was investigated.
The problem of effective and inexpensive purifica-
tion of wastewater of galvanic industry to remove
heavy metals and, in particular, chromium(III) ions is
of great importance for the national economy. Pres-
ently, the main technique for removal of chromi-
um(III) ions from solutions is their neutralization and
precipitation in the form of Cr(OH)
. The after-
purification to an MPC level (0.5 mg l
requires expensive synthetic cation exchangers . It
has been proposed to use inorganic carbonate-con-
taining sorbents for recovery of heavy metals .
The use of industrial wastes as sorbents is of particular
interest from the standpoint of cost efficiency and
The cumulative, embryotoxic, and mutagenic ef-
fects of chromium(III) ions have been well studied.
The possibility of removing these ions from waste-
water is the subject of the present study. We propose
to use for this purpose an industrial waste containing
calcium and magnesium carbonates as a readily ac-
cessible and inexpensive sorbent (for brevity, referred
to as sorbent in what follows). The sorbent is a finely
disperse white powder with creme tinge. According to
the histogram in Fig. 1, the main fraction (49.2%)
used in the study contains particles of size 0.253
The following elements were found in the sor-
bent (%): Ca 26.5 + 0.1 (titrimetry), Mg 2.69 + 0.05;
Fe 2.00 + 0.02; Al 1.10 + 0.05 (spectrophotometry,
KFK-2 apparatus), Si 2.4 + 0.1 (gravimetry), Na
0.19 + 0.01 (flame photometry, Flapho-4 photometer);
Ni 0.0010 + 0.0005, Pb 0.0013 + 0.0005, Cu 0.0047 +
0.0005 (spectral analysis, LMA-10 spectrograph).
Using an X-ray analysis (DRON-2 apparatus, Cu
radiation), we found the following phases: CaCO
O, b- and g-Fe
A water extract of the sorbent at dry substance to
water ratio of 1 : 5 has pH 8.74 + 0.05 (the pH values
were measured with an I-120M ionometer).
Hydrolytic equilibria for chromium(III) ions were
calculated for the 100 mg l
corresponds to the average content of chromium ions
in real wastewater . As a result, the pH ranges
Fig. 1. Granulometric composition of the sorbent. (F) Con-
tent of a fraction in the sorbent and (R) particle size.