Safety and Technical Feasibility of Sustainable Reuse of Shale Gas Flowback and Produced Water after Advanced Treatment Aimed at Wheat Irrigation

Abstract

Treatment and reuse of flowback and produced water (FPW) from shale gas extraction for agricultural irrigation has often been proposed as a sustainable alternative to disposal via deep-well injection. Here, we investigate the effects of FPW on the germination period, macroscopic growth, element enrichment, and grain gene expression of wheat upon dilution and advanced membrane treatment of the liquid stream. Compared to tap water, irrigation with treated FPW shortened the germination time, slightly improved the seed vigor index, and ensured a similar germination rate. On the other hand, the biomass and grain yield of mature wheat irrigated with treated FPW and with FPW diluted to 5% groups decreased compared to tests using tap water. After a whole growth cycle of wheat, higher concentrations of nutrients, such as K, Ca, and Mg were enriched in mature wheat tissue irrigated with treated FPW. However, the Pb and Cr contents of mature wheat grains treated with three types of irrigation waters exceeded the standard to varying degrees. A total of 1973 differentially expressed genes were mainly related to binding, catalytic activity, cellular process, metabolic process, and cell part, more than half of which were upregulated and induced by irrigation with treated FPW. These findings provide critical guidance for the reuse of treated shale gas FPW for agricultural application from the perspective of plant uptake of toxic elements, as well as crop and human health risks.

Performance Evaluation of a High Salinity Produced Water Treatment Train: Chemical Analysis and Aryl Hydrocarbon Activation

“…However, this was done to determine any possible correlation to organic concentrations in PW and inorganic toxicity to worms, not to test the individual treatment processes. Yang et al studied the effects of using treated PW for the germination and irrigation of wheat . However, the PW tested was the final product water from a six-stage wastewater treatment facility; water from the individual processes was not studied.…”

“…Yang et al studied the effects of using treated PW for the germination and irrigation of wheat. 16 However, the PW tested was the final product water from a six-stage wastewater treatment facility; water from the individual processes was not studied.…”

Technical Feasibility of Extraction of Freshwater from Produced Water with Combined Forward Osmosis and Nanofiltration

“…Two common handling methods of PW are disposal and reuse [6,11,12]. The latter exploits PW as a potential freshwater resource [6], according to United Nations Sustainable Development Goals 6 and 12 [https://sdgs.un.org/goals (accessed on 29 April 2024)].…”

“…The applications can range from reinjection into oil or gas reservoirs for enhanced oil recovery to, potentially, high-end uses in the agricultural and civil sectors [13]. PW requires intensive treatment to be used outside the energy sector, such as for irrigation purposes, even when these do not involve crops or products for human consumption [12]. Therefore, it is essential that we develop a series of strategies for PW treatment and for the extraction of water to comply with the necessary standards [5,14,15].…”

Efficacy of Nanofiltration and Reverse Osmosis for the Treatment of Oil-Field Produced Water Intended for Beneficial Reuse

“…Technological development in horizontal drilling and hydraulic fracturing has increased unconventional oil and gas (UOG) production and enhanced the energy security of the U.S . The extraction of UOG requires an extensive amount of fresh water and produces a significant volume of wastewater. , The UOG produced water is dominated by high salt concentrations and hazardous chemicals , that may cause human and environmental health issues. ,− Moreover, considering that many shale plays are located within or close to areas that suffer from severe water scarcity, − the intensive water usage of UOG production can lead to competition with agricultural, municipal, and industrial water demands . As a result, there is an urgent need for developing proper produced water management strategies to address the dual challenges of water scarcity and pollution associated with UOG production.…”