221
Chemistry and Technology of Fuels and Oils, Vol. 39, No. 4, 2003
ECOLOGY
EFFECT OF ALUMINUM ION ON COAGULATION OF DISPERSE SYSTEMS
IN PLANT WASTEWATERS.
Physicochemical Principles of Prediction
V. F. Sorochenko UDC 629.162
____________________________________________________________________________________________________
National Technical University Kiev Polytechnic Institute, Ukraine. Translated from Khimiya i
Tekhnologiya Topliv i Masel, No. 4, pp. 48 53, July August, 2003.
0009-3092/03/39040221$25.00Ó2003Plenum Publishing Corporation
Based on new physicochemical and probability concepts concerning rapid coagulation of lyophilic
disperse systems (LDS), a theory that correlates this phenomenon with the amount and state of
metal ions is developed. The amount of these ions decreases inversely proportionally to the
difference between the charge of the metal ion and the number of OH groups in its inner coordination
sphere in coagulation according to a multilayer adsorption mechanism. For a dose of metal ions
less than or equal to the concentration of the initial LDS, coagulation takes place according to a
multilayer adsorption mechanism.
Methods of manufacturing aluminum hydroxide compounds [1-3] and zero-waste use of these compounds
in deposit -free operation of water-return cycles and sewage treatment [4-6] in oil refineries (OR) are examined
in some detail in the literature. However, the effect of the basicity (number m of OH
-
groups joined by a M
7+
metal ion with charge z
+
within the limits of 0£m£z to its inner coordination sphere) of the partially hydrolyzed
metal ion M
(z-m)+
on the amount causing distribution of LDS particles during their fast coagulation has not yet
been determined.
For this reason, according to [7], there are no equations for unambiguous determination of the dose of
coagulants in consideration of the variety of properties of disperse systems. Methods of experimental
coagulation or empirical equations for a preliminary calculation are still the most widely used [8, 9].
We elaborated the physicochemical principles for the theory of the effect of metal ion basicity on the
dose (concentration) that causes phase distribution of LDS particles during fast coagulation.
In elaborating the electrostatic concepts of the DeryaginLandauVerveyOverbeek (DLVO) coagulation
theory and current concepts concerning the stabilizing effect (solvation [10] to a state of thermodynamic stability
of surface energy) of polymolecular hydrate layers of LDS particles [11], we considered the effect of a change
in the basicity (m ® z) on the dose
P]
0
'
(mg/dm
3
) of metal ion (in terms of M
2
O
3
) causing phase distribution
of the initial concentration
/'6
&
(mg/dm
3
) of LDS particles.
The Arrhenius equation [12]
57(
IRU
D
IS.
H
(1)
establishes the dependence of the rate constant K
for
of formation of water from H
+
and OH
-
ions on the
product of steric p and frequency f factors on factor
57
D
(
H
reflecting the fraction of the total number of