PDF Publication Title:
Text from PDF Page: 022
polarity of the electrodes at regular time intervals [163]. Consequently, diluate and concentrate channels are inverted and the reverse electric field promotes the periodic removal of electrically- charged foulants (e.g. colloids or organic matter) deposited on membranes surface. In this way, detached particles are entrained by the flowing solutions and discharged with the exiting streams (“off-specification” outlet), which are therefore disposed back to the sea (or to another receiving body) for a time interval allowing the complete cleaning of the feed compartments, typically ranging from a few seconds up to 1-2 minutes [163]. EDR adds complexity to the process as it requires a triggering control unit, electric control systems to change polarity and automatic valves for compartments switching . In addition, some of the feed is wasted during the “off-spec transition”, which leads to a reduction in the conversion rate of the process. Nevertheless, EDR offers significant advantages in terms of minimisation of cleaning procedures and pre-treatments and avoids the presence of acids tanks, complexing agents tanks, dosing pumps and pH controllers inside the desalination plant [163]. Moreover, the polarity reversal technology is able to operate under extreme conditions, such as salt supersaturation, with examples of plants operating under a super-saturation level of CaSO4 higher than 175% [164]. More importantly, EDR has allowed the operation of brackish water ED industrial plants for more than 30 years, with IEMs lifetime reaching up to 10-15 years. More recently, a concept similar to polarity reversal has been investigated, namely the pulsed electrical field (PEF) [153, 165, 166]. The PEF operating mode consists of discontinuously applying the electric field and generating a constant current, leaving some time intervals without any electric field applied. This method is claimed to reduce membrane fouling, thus increasing process performances, by disturbing the deposition of charged species. In addition, a reduction of the polarisation layer has also been experienced [165, 166]. PEF has been recently compared with EDR, showing similar performances or even lower energy consumption under certain conditions [167]. 4. Hydrodynamics and mass transport in electrodialysis: from fundamentals to recent developments The role of hydrodynamics and associated phenomena of mass transport is crucial in determining the performance of ED stacks and the capital and operating costs of the process. It is well known that mass transfer limitations and non-Ohmic voltage drops arise because of the so called “concentration polarization phenomena” and can be mitigated by convective motions enhancing mixing. The energetic cost of the process may also be affected by the power consumption for pumping the solutions through the channels. Moreover, the channel features, which are essential for 22PDF Image | Electrodialysis for water desalination
PDF Search Title:
Electrodialysis for water desalinationOriginal File Name Searched:
Review_ED-self-archived.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)