Reuse of Industrial Wastewater Effluent in the Petrochemical Industry
337
FROMCCSl
FROMCCS2
FROM
OWS
DAF
GRAVITY
THICKENING
LONG TERM
STORAGE
and
SEPARATION
FILTRATION
FILTRATE
TOCCSl
CAKE TO
CEMENT KILN
OILY PHASE TO PRODUCTION
SLUDGE TO LAND TREATMENT
WATER TO DGF
Fig. 2
Schematic description of the sludge treatment
4 Specific Problems in Biological Treatment
4.1 Inhibition
Biological treatment of petrochemical wastewater, pretreated by gravity
separation, flocculation, and dissolved air flotation is feasible; however, Galil et
al. (1988) reported several problems, which have to be considered in planning,
design, and operation of the treatment system.
Efficient removal of BOD and phenols could be achieved by a suspended
growth pilot and by a laboratory system when organic loading rates did not exceed
0.15 Kg BOD per Kg MLVSS per day. This is a rather low specific loading rate,
indicating in itself slow kinetics. A more detailed kinetic analysis revealed high
values of the apparent saturation constant, Ks(ap) in the Michaelis-Menten rate
expression:
(1)
qrnax, being the maximal loading rate, S the soluble organic substrate
concentration. The values of Ks(ap) were found to be directly dependent on the