Water & Wastewater Asia March/April 2024

HOTSEAT
of 95-100°С. It requires bulky
equipment and a large production
floor space. A generalised typical
diagram of an industrial plant for
phenol-containing wastewater
treatment is shown in Fig. 1.
FERROMAGNETIC PARTICLES AVS
IN WASTEWATER TREATMENT
PROCESSES
A vortex layer device (AVS) is a system
consisting of an operating chamber
placed in an inductor of a rotating
electromagnetic field (Fig. 2).*
The operating chamber of the
device is a pipeline wherein driven
by a rotating electromagnetic
field, the steel, cylindrical-shaped
ferromagnetic particles move along
complex trajectories that contact
the substances running through the
pipeline, collide with one another
and the operating chamber walls.
At the same time, various physical
phenomena arise in the operating
zone of the device. This is due to
water and chemical agent mixing,
as well as a more complete and
intensive course of chemical
reaction achieved. It takes a few
kilowatts of active power to create
a rotating electromagnetic field.
Thus, the presence of an AVS makes
wastewater treatment complexes
more compact as mixing occurs in
stream and no longer requires large
mixing tanks. It is energy-efficient
due to the lack of mechanical mixers
needed, and also saves on expensive
chemical agents due to the rapid
course of chemical reactions.*
METHOD FOR TREATING
PHENOL-CONTAINING
WASTEWATER WITH AVS
The study paper proposed a new
continuous method for treatment of
wastewater containing phenol and
other organic impurities through
the use of a ferromagnetic particles
AVS.* The study for maturing this
method in an AVS was carried out
Parameters
Phenol of
formaldehyde
resins
Wastewater of production facilities
Phenol of epoxy
resins
Fig. 2: General view
of AVS: 1 – protective
bushing; 2 – inductor of
rotating electromagnetic
field; 3 – inductor
housing; 4 – operating
chamber made of
non-magnetic material;
5 – ferromagnetic
particles
Phenol of
diphenylolpropane
Phenol (g/dm 3 ) 0.5-5 0.1-0.3 10
Sulfuric acid (%) 2-5 – 10
Formaldehyde (g/dm 3 ) 2-12 – –
Diphenylolpropane (g/dm 3 ) 3-5 1.5 9.3
Methanol (g/dm 3 ) 0.8-10 5 –
NaCl (g/dm 3 ) – 12.7 –
NaOH (g/dm 3 ) – 0.5-10 –
Dry residue (g/dm 3 ) 0.5-8.5 28.0 45
with artificially prepared wastewater
that had the concentration of phenol,
acids, and impurities similar to
the content of these constituents
in wastewater of real production
facilities. The characteristics of
wastewater understudy are shown in
Fig. 3.
The process flow diagram of the plant
for treatment of phenol-containing
wastewater through the use of AVS
is simpler in terms of hardware and
process-related design, compared to
the industrial process flow diagram
(Fig. 4).
The phenol-containing wastewater
coming from the points of its
occurrence enters the balancing tank
for mixing and phenol concentration
equalising (Fig. 4). The wastewater
— previously analysed for phenol
content — is pumped from the
balancing tank to the AVS wherein
an oxidising agent — a sodium or
Fig. 3: Wastewater
characterisation
48 Water & Wastewater Asia | March-April 2024