Date of Award

12-2010

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Hydrogeology

Advisor

Castle, James W

Committee Member

Rodgers Jr. , John H

Committee Member

Murray Gulde , Cynthia

Abstract

Oilfield produced waters (OPWs) are brought to the surface when oil reservoirs contained in water-bearing geologic units are extracted. Large volumes of OPW present environmental challenges concerning disposal, as well as potential opportunities for beneficial use if constituents posing risk can be remediated. In this study a pilot-scale constructed wetland treatment system (CWTS) was specifically designed to treat an OPW from sub-Saharan Africa for use in irrigation and livestock watering. Three major objectives were to: characterize and identify constituents of concern in the OPW in terms of beneficial use, evaluate treatment performance of a pilot-scale constructed wetland treatment system for simulated OPW, and conduct seed germination and early growth (SG/EG) bioassays to confirm suitability of post-treatment simulated OPW for irrigation.
Through a risk assessment approach incorporating exposure pathways and calculated risk quotients, Fe, Mn, Ni, Zn, and oil and grease were identified as constituents of concern (COCs) in the OPW for irrigation and/or livestock watering. Chemical and biological performance of the pilot-scale CWTS designed for these COCs indicated decreased aqueous concentrations (Fe, Mn, Ni, Zn, and O&G) and decreased toxicity to P. promelas and C. dubia after treatment. SG/EG bioassays demonstrated greater values for early growth response parameters (i.e. root and shoot length and mass) for seeds germinated in post-treatment waters compared to pre-treatment simulated OPW. Combined, the characterization, pilot-scale experiments, and SG/EG bioassays indicate the OPW has a high potential for treatment and beneficial use based on chemical and physical composition, volume, treatment kinetics, and local need for water for irrigation and livestock.

Included in

Hydrology Commons

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