Date of Award


Degree Type


Degree Name

Doctor of Philosophy in Civil and Environmental Engineering


Civil and Environmental Engineering

First Advisor

Leon Thiem


Biological prosesses for treating refinery industry wastewater for re-use were studied. A pilot-scale biological reactor was constructed to simulate the activated sludge treatment process.

Actual refinery industry wastewater collected from a regional refinery and spiked with additions of selected priority organics was fed at a rate of 1.3 liters/hour into a 6-liter pilot plant having a hydraulic retention time of 4 hours. Activated sludge (AS) which was augmented by additions of powdered activated carbon (PAC) at dosages of 10, 50 and 120 mg/L was evaluated. The AS process removed 70-80% of the B005, COO and TDC. With the addition of PAC, removal efficiencies of the indicator compounds rose to 80-95%. The sludge physical parameters and kinetic constants were determined with and without the addition of PAC to the AS.

PAC additions to the AS increased the amount of biomass in the reactor. Volatile compounds (benzene, chloroform, ethylbenzene, toluene, m-xylene and o-xylene) were removed from the reactor by volatilization which occurred from air stripping. PAC alone (without AS) was primarily responsible for removing base and acid/neutralextractabl e compounds (2,4-dimethylphenol, fluorene, naphthalene and pyrene).