During laboratory studies, the removal of residual iron ions in natural water during
aeration were investigated. Parameters of initial water: water hardness = 4,90 mg-
eqv/dm
3
; Са
2+
= 3,55 mg-eqv/dm
3
; Mg
2+
= 1,35 mg-eqv/dm
3
; рН = 8,03 mg-eqv/dm
3
; SO
−
2
4
= 0,5 mg-eqv/dm
3
; Cl
-
= 2,90 mg-eqv/dm
3
; alkalinity = 6,05 mg-eqv/dm
3
;
Fe
total
= 0,7; 1,0; 2,0; 5,0; 7,0; 10,0 mg-eqv/dm
3
.
There are many approaches and methods to reduce the amount of iron ions in
water treatment technology, but in the context of sustainable development, the search
for simple, autonomous, energy efficient and highly effective methods for the
purification of natural and sewage water is one of the promising areas of scientific
research. Investigation of iron ion removal processes from waters of various origins is
an actual problem. Many factors influence this process. In order to evaluate the
efficiency of the iron ions removal processes, a detailed study of each factor that may
affect the process is required.
Changing in the concentration of iron in time. Analysis the initial data on the
change in the concentration of divalent and trivalent iron ions shows a significant
decrease in Fe
2+
ions, as can been seen from in Figure 6.
Initial concentration, mg/dm
3
: 1 - 0,5; 2 - 1; 3 - 5 ;4 - 10 ;5 - 15 ;6 - 20
Figure 6. Change in the concentration of divalent iron in time
At low concentrations of iron ions, depending on the time, the rate of transition of
Fe
2+
ions in Fe
3+
is much greater than that observed with high iron ions content in the
sample; means that at the concentrations of 0.5-1 mg/dm
3
there is the most intense
reduction of ion of divalent iron.
Change in the concentration of iron ions, depending on the area of contact of the
sample with air. In this study, the dependence of the processes of the transition of ions
of divalent iron into insoluble form was studied in the concentration of the model
solution of Fe
2+
= 5 mg/dm
3
. The data of the experiment of reducing the concentration
of iron ions (II) are indicated by counting their number on a proportional reduction in
the volume of initial samples (taking into account evaporation processes). The results
of the experiment with the corresponding recalculation are shown in Table 5.
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