Oil and gas production wells generate large volumes of water mixed with hydrocarbons (dispersed and dissolved), salts (ions), and solids. This ‘produced water’ (PW) is a waste stream that must be disposed of appropriately. The presence of toxic hydrocarbons and ions in PW makes it unsuitable for surface discharge or disposal in groundwater resources. Thus, PW is often injected into deep geological formations as a disposal method. However, the supply of global water sources is diminishing, and the demand for water in industrial, domestic, and agricultural use in water-stressed regions makes PW a potentially attractive resource. PW also contains valuable elements like lithium and rare earth elements, which are increasing in global demand. This review article provides an overview of constituents present in PW, current technologies available to remove and recover valuable elements, and a case study highlighting the costs and economic benefits of recovering these valuable elements. PW contains a promising source of valuable elements. Developing technologies, such as ceramic membranes with selective sorption chemistry could make elemental recovery economically feasible and turn PW from a waste stream into a multi-faceted resource.
Mechanically robust optical homogeneous polyimide (PI) films with desirable atomic oxygen (AO) erosion duration were fabricated by initially synthesizing amine-functionalized hyperbranched polysiloxane (NH2-HBPSi), then reinforcing the pristine polyimide skeleton with it via copolycondensation reactions. NH2-HBPSi macromolecule imparts desirable AO survivability to the resulting hybrids. The mass loss per unit area of hybrid films had a downward trend with rising NH2-HBPSi content and AO dose before the complete silica protective layer was formed. It has been proven by the experiments in an underground simulated AO environment. It decreased to 1% of that of pristine polyimide when NH2-HBPSi accounted for 30% of the solid content after 24 h AO attack. The stable thickness uniformity that can meet the Rayleigh criterion was achieved in a 30 wt% HBPSi PI film, mainly due to the selection of the best process parameters. Meanwhile, 30 wt% HBPSi PI demonstrates satisfactory mechanical properties, with a tensile strength of 228.9 MPa and elongation at break of 7.3%. The characterization of scanning electron microscopy confirmed that pristine polyimide was substantially eroded after AO exposure while the surface morphology of 30 wt% HBPSi polyimide showed no evident change. The low AO erosion yield and prominent film thickness uniformity may find extensive usage in ultra-lightweight space diffractive optical elements (DOE) working in low earth orbit (LEO).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.