K. Karakulski et al., PURIFICATION OF BILGE WATER BY HYBRID ULTRAFILTRATION AND PHOTOCATALYTIC PROCESSES, Separation and purification technology, 14(1-3), 1998, pp. 163-173
Investigations have been performed on the purification of bilge water
by a combination of ultrafiltration and photocatalytic processes. The
separation of oil from bilge water obtained from Szczecin-Swinoujscie
harbour was performed on a laboratory-scale ultrafiltration pilot plan
t with tubular membranes made from poly(vinyl chloride) (PVC), polyacr
ylonitrile (PAN) and polyvinylidene fluoride (PVDF). The examined memb
ranes with MWCO of 70 kD for PVC and PAN and 100 kD for PVDF produced
a permeate with an oil content less than 15 ppm. Rejection of chemical
oxygen demand (COD) was in the range 92-96% for the ultrafiltration t
reatment. The permeate is generally of acceptable quality for direct d
ischarge into the Baltic Sea district in accordance with present legis
lation. Further treatment of UF permeate has been performed by heterog
eneous photocatalytic oxidation in order to remove the residual oil. T
he photocatalytic process was carried out using titanium dioxide based
catalyst. The complete decomposition of oil was achieved after 2 h of
UV illumination using a K-TiO2 photocatalyst with content amounting t
o 0.8 g/dm(3) and after 3 h of UV illumination using 0.8 g/dm3 of KOH/
TiO2 photocatalyst. The photocatalytic process was found to be very ef
fective for the permeate reclamation. (C) 1998 Elsevier Science B.V. A
ll rights reserved.