Removing Unwanted Substances from Fracking Waste
Delivered March 24, 2020. Contributor: Methody G.
Goals
To provide an overview of the waste product being produced during the fracking process and to provide the cost associated with removing the polutants from the waste water.
Early Findings
- According to data from a study done by Downstream Strategies, to frack a single well takes 4.3 million gallons of water on average.
- The fracking process involves three separate stages that produces different types of pollutants: 1) the well drilling and completion stage, 2) the well stimulation stage, especially in hydraulic fracturing, and 3) the well production stage.
- The well drilling and completion stage produces drilling fluids (drilling muds)
, cuttings
, and wastewater.
- The well stimulation stage usually produces fracturing fluid returns and wastewater while the final production stage produces waste water plus the final product, usually oil or gas.
- The fracturing fluid consists of 98 to 99% water by volume plus 1 to 1.9 vol% of proppants and typically less than 1 vol% of additives. Proppants are small grains of sand or ceramics.
- There are many types of chemical additive but the most common ones include biocides, buffers, breakers, corrosion inhibitors, crosslinkers, friction reducers, gelling agents, surfactants, and scale inhibitors.
- The final wastewater byproduct usually contains chemicals, heavy metals, excess salts, carcinogens like benzene and naturally occurring radioactive materials. The final wastewater product was also found to contain ammonium and iodide, substances that encourage the formation of toxins like carcinogenic disinfection byproducts.
- In most cases, wastewater is either treated in wastewater decontamination plants or isolated in specific ponds. However, a paper from August 2017 claimed that the process of decontamination is very inefficient.
- The most common pollutants that were found included surfactants, polyaromatic hydrocarbons, radionuclides, salts, and metals.
Research proposal:
Only the project owner can select the next research path.