height of the medium was 110.0 cm, which represented a volume
of 2159.85 cm
3
. The filtration material used was sieved through
the sieves, and the grain size was in a range from 1 to 2 mm. The
filtration conditions are shown in Table 4.
Based on the results of the “treated water” analyses, the iron
concentrations after aeration and sedimentation moved in a range
from 0.37 to 0.85 mg/l (mean concentration = 0.56 mg/l), and the
manganese concentrations were in a range from 0.57 to 0.88 mg/l
(mean concentration = 0.70 mg/l). The pH value was in a range from
8.26 to 8.38 (mean value = 8.3).
The filtration device was in operation for several months. The
Charts 1 – 2, which demonstrate the removal of iron and manganese
from the water were prepared based on the measured values.
It was necessary to backwash the filtration media by return flow
every second day. After some time, as can be seen in charts 3 and
4, the concentration of manganese increased in the treated water
over 0.05 mg/l. Both media were regenerated by 0,5 % potassium