![]() Each method was able to eliminate only one of the disadvantages of conventional EDI. Previous studies have found ways to eliminate leakage issues by using spiral-wound configurations or the channeling problem by immobilizing the resin using magnetic fields. Another disadvantage of loose resins in EDI systems is the uneven distribution of flow within the channels which decreases the separation efficiency. This loose resin structure complicates sealing between compartments and leads to leakage of ions from one compartment to another due to convection instead of diffusion. The ion exchange resins are inserted into a pair of anionic- and cationic-exchange membranes loosely. ![]() Įven though there are major advantages of EDI over ED and ion exchange processes, there are also several disadvantages of EDI. Membrane technologies also have essential advantages such as the simplicity of operation, high flexibility and stability, low energy requirements, high economic compatibility, and easy control of operations and scale-up under a broad array of operating conditions and good compatibility between different integrated membrane system operations. Wastewater treatment technologies using membranes appear to be the more practical and feasible strategies to overcome one of the primary issues the world faces the shortage of freshwater supplies and degradation of water quality. Membrane-based technologies have become a remedy for the removal of particulates, ionic, gaseous, and organic impurities from aqueous streams without the use of hazardous chemicals due to their reliability and cost-effectiveness. If the wastewater can be reused or reduced, then the expenses from transportation and disposal can be decreased or eliminated. Hence, there is a need for on-site wastewater treatment to minimize the freshwater use and damaging effects of fracking wastewater. ![]() The fracking wastewater contains divalent cations (such as calcium and magnesium) and monovalent ions (such as sodium and potassium) as well as other anions, chemicals, and bacteria. Produced wastewater contains a high concentration of dissolved solids which often exceeds 50,000 parts per million (ppm) and is about 2–6 times higher than seawater concentration. Hydraulic fracturing, commonly known as fracking, is used to release natural gas and oil and also uses large amounts of water in its production. Besides this attention, excessive freshwater use can create hardships for industries, households, farmers, and wildlife. Specifically, the consumption of large volumes of fresh water and the generation of highly contaminated wastewater has drawn negative attention from both the public and environmental groups. For instance, in various industries such as the semiconductor, pharmaceutical, power, and hydraulic fracturing industries, an average facility can use 2 to 4 million gallons of water per day. The increase in population and industrial development has triggered physical and economic water scarcity. This indicates the importance of resin size in the performance of wafers. After grinding the strong cation resins displayed similar behavior (more consistent current efficiency and preference for transporting divalent ions) to the strong cation resins in powder form. To further understand the impact of particle size, resins in the bead form were ground into a powder. Moreover, the strong cation exchange resins in powder form generally performed better in wafers than those in the bead form for the selective removal of divalent ions (selectivity > 1). Results also revealed that weak cation exchange resins favor the transport of the monovalent ion (Na +) while strong cation exchange resins either had no strong preference or preferred to transport the divalent ions (Ca 2+ and Mg 2+). The current efficiencies were high for all the resin types studied. #Smith micro amberlight mac#This work reports the performance comparison of four commonly used cation exchange resins (Amberlite IR120 Na +, Amberlite IRP 69, Dowex MAC 3 H +, and Amberlite CG 50) and their influence on the current efficiency and selectivity for the removal of cations from a highly concentrated salt stream. ![]() Because every excess ion transported increases the operating costs, the selective separation offered by WE-EDI can provide a more energy-efficient and cost-effective process, especially for highly concentrated salt solutions. Unlike filtration processes, WE-EDI can be used to selectively remove ions even from high concentration systems. Wafer-enhanced electrodeionization (WE-EDI) is an electrically driven separations technology that occurs under the influence of an applied electric field and heavily depends on ion exchange resin chemistry. ![]()
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