31 July 2020
CMMS researchers explore algal-based produced water treatment
The research hopes to unlock new and economical ways to both treat and use produced water.
A Lamar University research group is investigating the use of algae as a produced water pre-treatment step. A team led by assistant professor Thinesh Selvaratnam and associate professor Nicholas Brake believes that by growing algae in the water, certain constituents can be addressed while generating some of the materials needed to produce biofuels, animal feed, pharmaceutical products and cosmetic pigments.
Funded by an internal seed grant from the university’s Center for Midstream Management and Science (CMMS), the researchers will experiment with a variety of algae to establish which strains are more appropriate for large-scale use. So far, the team has determined that the strain Galdieria sulphuraria performs well for removing nitrogen and several heavy metals from produced water. Chlorella vulgaris and Scenedesmus sp. are also being tested; however, it is too early to determine how effectively they can remove target constituents.
Selvaratnam told WiO that the long-term goal is to install algae photobioreactors at well pads or centralized produced water collection facilities, in much the same way as his similar projects for municipal wastewater treatment facilities have been set up.
The team is currently conducting bench-scale photobioreactor experiments. In the coming months, several 15-liter and 100-liter reactors will be placed in an outdoor greenhouse at the university for pilot-scale testing. To get to this point, though, the project will require more help from the industry.
“We are at a moment where we want actual samples," Selvaratnam explained. "Right now, the team is using samples prepared to simulate produced water from various basins in the US, including the New Mexico Permian Basin. However, that's not true produced water.”
Once Selvaratnam’s team has done all they can with the samples, they will be given to Dr. Brake’s research group to investigate the possibility of using produced water for applications such as concrete production. That study is also sponsored by the state-funded CMMS, which was established as a liaison between academia and the midstream oil & gas industry.