The first stream passes through the complicated treatment process for oil
and phenol removal, and is led to the aerobic bio-treatment plant. The second
stream passes through the local purification unit, where the coagulation
and flotation processes are used for pretreatment. The third stream is collected
in several ditches on the foot of the ash dump, one part is taken back
for the semicoke extinction, another, less polluted part, is discharged to the
Gulf of Finland.
The main treatment stages for the phenolic effluents from the Kiviter
process are: 1) deoiling (oil separation) [13], 2) dephenolation, and 3) biological
treatment.