Biological treatment process for removing petroleum hydrocarbons from oilfield-produced waters.

摘要

During crude oil and natural gas exploration and production, large volumes of "produced water" are concurrently recovered. Produced water is the largest volume waste stream in the exploration and production process of oil and gas. During the later stages of production, it is not uncommon to find that produced water can account for as much as 98% of the extracted fluids. In 1987, the Environmental Protection Agency (EPA) estimated the total onshore volume of produced waters generated in the United States as being 11.7 billion barrels (EPA, 1987). During 1990, Gulf of Mexico oilfield operations produced 8.7 million barrels of produced water (Menzie, 1991). It has also been found that with continuous pumping, the ratio of produced water generated continues to increase significantly. At most production sites, the produced water is separated from the crude oil in gravity separators and discharged into surface pits for evaporation and/or subsequent well reinjection. During evaporation, the waters in these surface pits become laden with high concentrations of crude oil and pose a severe threat to both surface and ground water environments.;Therefore, a research project was conducted to evaluate the performance of laboratory (batch) and field (continuous-flow) biological treatment systems in removing petroleum hydrocarbons from several southeastern New Mexico oilfield produced waters. The biokinetic coefficients; maximum specific growth rate (