The Use of Bioremediation As a Potential Treatment for Produced Water

A byproduct from the production of natural gas and petroleum is produced water. Large volumes of produced water are generated annually and can be as high as 2 million gallons per unconventional well. Produced water can be reused in the fracking process, injected in storage wells after use, or treated before being released into the environment. One possible treatment option, bioremediation, uses naturally occurring bacteria in soil around the sites of fracking locations to remove some of the toxins, specifically hydrocarbons found in produced water. Using this method, produced water can be inoculated with these bacteria to potentially reduce the number of toxins present in the water. In this experiment, bacteria from well sites in the Appalachian region were cultured and used to study their effectiveness in treating produced water. A pure culture of bacteria from Saskatchewan that has been shown to degrade hydrocarbons was also cultured. These samples were grown under three conditions; nutrient media with crude oil, nutrient media with produced water, and nutrient media with a mix of crude oil and produced water. A total of 36 samples were included, 3 replicates per treatment and bacteria culture. Water quality samples were taken and sent to the West Virginia University analytical lab where they were tested for strontium, barium and chloride ion concentrations in the samples taken at 0, 30 and 90 days. The results were then compared to the heat killed samples to determine if the bacteria had any effect on the produced water. It was found that both bacteria reduced the conductivity in samples with a mix of produced water and crude oil. It was found that bacteria from soil samples had a greater reduction of in ion concentrations in samples with just crude oil while the pure culture bacteria was more effective in samples with just produced water.