Membrane-based treatment of petroleum wastewater

Abstract

Oil and gas exploration activities through conventional and unconventional approaches are accompanied by massive volumes of wastewater generated. The wastewater is originated either from the naturally saturated rocks or from hydraulic fracturing activities injecting water-based slurry and is known by produced water (PW) owing to its coproduction with hydrocarbons. With the growth in global population and the lack of natural water resources, the application of the well’s hydraulic fracturing consuming massive volumes of fresh water is being limited. Besides, the PW containing some toxic organic compounds such as polycyclic aromatic hydrocarbons has triggered concerns about its environmental implications. Therefore management and treatment of the large volumes of PW streams are needed for the recycling and reuse of this water. Earlier recycling and reuse treatment approaches were limited to the simple separation of oil and grease. However, the stringent environmental regulations required the development of advanced treatment technologies and pushed toward the implementation of membrane-based processes capable of providing high water product quality. Processes such as microfiltration and ultrafiltration guarantee the removal of suspended particles and macromolecules from the PW respectively. Whereas, the high-pressure-driven processes represented by nanofiltration and reverse osmosis which have been considerably investigated for PW treatment are capable of stripping off the dissolved traces and multivalent ions. Notwithstanding the successful operation of the pressure-driven membrane processes, forward osmosis (FO) utilizing the natural osmotic pressure difference is currently under extensive investigation for PW treatment. FO when operated as an osmotic concentration process is a cost-effective membrane treatment technology for reducing the volume of PW from oil and gas fields. Furthermore, membrane distillation can be considered as a promising desalination technology for shale oil and gas PW with salinity up to 350,000 mg L−1. Lastly, other membrane processes such as electrodialysis (ED) and electrodeionization exploiting the electrical power are also evaluated for high salinity PW treatment and reported studies have shown successful treatment of PW to drinking water standards with 90% removal of total dissolved solids using ED. In this chapter, the wastewater problems facing the oil and gas industries pushing toward advanced treatment approaches relying on membrane-based processes are to be presented. There will be a comparison between the performance and operating principles of pressure, osmotically, electrically, and thermally driven processes for the treatment of PW and other wastewater streams from oil and gas industries. Besides, the reported outcomes of various conducted studies and experiments are to be compiled and compared. On the other hand, the operation challenges confronting the achievement of successful treatment by each membrane process are to be demonstrated.