THE EFFECT OF METAL OXIDES ON THE REFINERY EFFLUENT TREATMENT

Abstract

Metal Oxides (Titania TiO2, and Calamine (ZNO)) have been used as
tertiary treatment for Refinery Effluent treatment and wastewaters to
comply with the regulatory discharge limits and to oxidize persistent
compounds that had not been oxidized in the biological treatment. The
wastewater was provided by the Bandar Abbas Refinery. Although BOD
removal is high in this plant, a residual and persistent COD (Chemical
Oxygen Demand), besides a somewhat high phenol content remains. Three
catalysts were tested TiO2 (Aldrich), ZnO (Aldrich), and TiO2 (P25,
Degussa) by the UV radiation, the third being the most active. The
optimized conditions obtained with an experimental design were 3.0 (g/L)
TiO2 and pH=6.3. The use of hydrogen peroxide (H2O2) showed no
beneficial effect. Removal of 93% of phenols, 56% of dissolved organic
carbon (DOC), and more than 50% of oil and grease (OG) were achieved in
the catalytic process with UV radiation, improving the quality of the
treated wastewater.