1070-4272/02/7501-0086$27.00C2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 1, 2002, pp. 86!89. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 1,
2002, pp. 86!89.
Original Russian Text Copyright + 2002 by Aristova, Piskarev.
OF CHEMISTRY AND TECHNOLOGY
Kinetics of Phenol Oxidation under Flash Corona
N. A. Aristova and I. M. Piskarev
Nizhni Tagil Institute, Ural State Technical University, Nizhni Tagil, Sverdlovsk oblast, Russia
Research Institute of Nuclear Physics, Moscow State University, Moscow, Russia
Received March 6, 2001
Abstract-A study was made of the kinetics of phenol oxidation in a 3.5-l (liquid) tank at the initial chemical
oxygen demand of the solution of 20036000 mg O l
. The total current of flash corona electric discharge
from 50 electrodes was 3 mA.
The technical and economic requirements to the
quality and cost of wastewater treatment are now so
stringent that neither of the known treatment methods
fully satisfies them. Solving this problem requires the
use of different methods. The place and role of each
method are assessed in the development stage by
Phenol-containing wastewaters are widespread;
therefore, it is of interest to develop new processes for
their oxidation. In , we considered specific reac-
tions induced by electric discharge, namely, by flash
corona electric discharge generating a small volume
concentration of active particles, extremely high elec-
tric field intensity in the discharge space, and pulse
electric current. Also, we formulated the main features
of the electric discharge utilized for initiating the
reactions , described the reaction kinetics , and
showed that under certain conditions this reaction
has advantages over ozonation . In this work, we
analyzed the kinetics of phenol oxidation in a tank of
a sufficiently large volume and compared the results
with the characteristics of the known processes.
The liquid was treated in a 35 0 60 cm
a polyethylene bottom and 25-cm-high glass walls.
The tank volume was 50 l. Along the bottom perim-
eter and in the central area longitudinally, a contact
electrode made of aluminum wire, 3 mm in diameter,
was mounted. The tank was filled with 3.5 l of liquid.
Fifty discharge electrodes were placed at a distance
of 5 mm from the liquid surface. Each discharge elec-
trode was 12 cm long. The electrodes were mounted
on a Teflon sheet arranged under the tank cover. The
electrodes were separated from one another by 5 cm.
The 10-kV negative-polarity voltage was applied to
each electrode via the untying resistance of 10 MW.
The total discharge current from all the electrodes
was 3 mA. In the case of measurements in an oxygen
medium, before the voltage was switched on, the tank
was purged with oxygen at a rate of 3 l h
for 24 h.
During the experiments, oxygen was supplied at the
same rate. Oxygen was fed through the holes in the
tank bottom (through the liquid), and gases were re-
moved through the holes in the tank cover. During
experiments in air, the ventilation holes were addi-
tionally opened at the tank cover, and oxygen purge
was stopped. During treatment the liquid was mixed
by ion movement and by [electric wind], which is
a specific feature of the electric discharge mode
chosen . As working liquids served phenol and KI
solutions of different concentrations in distilled water.
The reagents were of chemically pure grade. The
phenol concentration was 84 (COD 200 mg O l
840 (COD 2000 mg O l
), and 2520 mg l
6000 mg O l
). The phenol concentration in the ini-
tial and treated solutions was determined by extraction
followed by spectrophotometry.
The active species yield Y was estimated by us
previously for the treated liquid volumes of 203
100 ml at the discharge current of 0.1 mA [2, 4].
These yields were as follows: Y(OH
) = 14.4, Y(H) =
18.0, and Y(O) = 2.5 mol mol
electrons (or mole-
cules per electron passed in the circuit). In  we
showed that in the presence of ozone the H atoms are
transformed into OH
radicals, and their total yield
) is about 32 mol mol
electrons, or 32 OH