During contact with air, water is enriched with oxygen and the oxidation potential
of the system increases. Therefore, a situation where the acidic medium is more stable
in the bivalent form of iron ions, and in alkaline - a trivalent form of the iron is
observed.
The initial concentration of the solution had an important impact on the results of
experiments. From the results it can be concluded that with the increase in the
concentration of iron in the sample, the effect of different pH values becomes more
pronounced. Thus, it can be said that at different pH values the following dependence
is observed: in the acidic medium a large number of ions of divalent iron, in alkaline –
the trivalent form of iron. Therefore, with an increase in the pH of the solution, the
concentration of iron (II) decreases, i.e., a greater transition of Fe
2+
ions in Fe
3+
is
observed. Thus, the highest content of trivalent iron in alkaline medium is observed at
concentrations of 2 mg/dm
3
and 5 mg/dm
3
.
Effect of dissolved oxygen on iron ions removal from waters of various origin.
Determination of oxygen in in water objectsis a very difficult task. Graphic
dependences of the influence of O
2
on the transition of Fe
2+
ions in Fe
3+
are presented
in Fig. 8.
a
b
c
Figure 8. The influence of O
2
on iron removal from a model solution with an
initial concentration of 1 (a), 5 (b), 10 (c) mg/dm
3
Graphic dependencies show that dissolved oxygen affects the transition of iron
ions. The more oxygen, the better is iron ions removal from aqueous solutions.
- 1802 -