Water Resources Research Act Program

Details for Project ID 2019OK218B

Four-step PW desalination process with zeolite and aAlumina membranes

Institute: Oklahoma
Year Established: 2019 Start Date: 2019-02-28 End Date: 2020-02-28
Total Federal Funds: $5,000 Total Non-Federal Funds: $10,000

Principal Investigators: David Lampert

Project Summary: Problem Description: Oil and gas production consumes and generates high volumes of water and wastewater, respectively. This wastewater, known as Produced Water (PW), has a high level of contamination with a complex chemical composition that depends on the recovery process and the geological formation. The most important components in PW are salts, oil & grease (O&G), benzene, toluene, ethylbenzene and xylene (BTEX), polycyclic aromatic hydrocarbons (PAHs), natural organic and inorganic compounds, etc. Salts cause problems in irrigation and create corrosion in materials such as metal pipes or concrete structures. Another problem that is crucial in Oklahoma is induced earthquakes caused by PW injection to disposal wells. Methods: In this project, a four-step desalination process will be examined. These steps are 1) softening which decreases scaling chances during the membrane processes. To do this step, calcium hydroxide (Ca(OH)2) will be added to raw sample; 2) pretreatment with sand filtration to remove large suspended solids; 3) microfiltration with a ceramic membrane to remove O&Gs; and 4) membrane desalination with α-alumina membrane. To reduce the costs and improve the efficiency, the effect of low-grade heat on membrane performance will be studied. Objectives: The main goal of this project is to develop a process to decrease hardness, remove suspended solids, remove oil from PW and prepare it for desalination. The rationale is that large amounts of desalinated PW could play a vital role in the central United States as a source of fresh water to decrease the disposal injection to deep formations that induces seismic activity and enable usage in agriculture and industry. Also, the treated PW could be reused in injection and fracking processes, which could reduce the large volume of fresh water used for oil and gas extraction around the world. The technology could also be used to desalinate brackish groundwater sources in Western Oklahoma. Moreover, researchers’ plan includes: investigate the species that cause membrane fouling, determine approach specifics to reduce the fouling process, and estimate the performance for a cost analysis. To achieve these goals, before and after each step, electrical conductivity (EC) will be measured to assess salinity. Inductively coupled plasma (ICP) methods including mass spectrometry (ICP-MS), optical emission spectrometry (ICP-OES) and an ion chromatography (IC) system will also be used to analyze the samples.