The Operation of Plants Treating Mixed Industrial Wastes
559
After discharging effluent No. 1 to the plant, the resulting purified water
concentration, S e can be calculated:
c
(4000.0,40) + 0,28 . 2/7 . 200 Λ ^ , . 3
S e =
4000 + 200
= °'
42 k S
/ m
Similarly, after conducting effluents No. 1 and No. 2 to the plant, S e = 0,530 kg/m
3
was calculated. In Table 4, the calculated, respective measured effluent concentrations are
included. For Unit No. 1, regarding that the calculated rise in effluent COD was only 20
mg/1, the discharge to the sewer was granted; but not for Unit No. 2, supposed to cause a
rise of 130 mg/1 in the effluent. Later on, as nevertheless both wastes were discharged to
the sewer, calculated rise in treatment plant effluent COD agreed well with measured
ones.
In Hungary the effluent COD serves as a basis for charging, and in the described case
the charge had to be paid by the sewer and treatment plant company (who, of course,
wanted to get it reimbursed from the discharger proper, the pharmaceutical factory). It is
evident that calculations like the above one may have economical and legal importance.