Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/1056083
34 Far Site December 2018 Water.desalination+reuse Ceramics solve radium SafBon Water Technology has developed a patented process for radium removal, which combines its ceramic at-sheet mem- branes with an upstream chemical/ physi- cal pre-treatment. The company acquired ceramic at-sheet specialists ItN Nanova- tion in 2016. The Cer@Sorp process enables the ceramic membranes to remove radium, and has proven a cost-e‚ ective solution. SafBon is now developing similar processes to target other constituents that are diƒ cult to remove. Nanostone's new design Nanostone Water has developed a segmented mono- lithic design for its ceramic membrane. The standard 1.9 metre-long … bre- reinforced plastic module has a … ltra- tion area of 24 me- tres square. It uses a patent-pending process and design, enabling exible and adjustable product design for di‚ erent applications — whether industrial, surface water, water recycling, or desalination. "The secret of the speci… c high perfor- mance of the membrane is in its nanostruc- tures," explains Nanostone Water chief science oƒ cer Dr Christian Göbbert. "The well-de… ned particle size distribution of the used particles is crucial for the pore struc- ture and properties of a ceramic membrane. Combined with a unique way to process and connect them, in a highly complex pore structure using speci… cally-designed nanoparticles, this leads to a superior ho- mogeneous pore structure, with a very nar- row pore size distribution, and long lasting, eƒ cient separation properties." Q & A M I T TA R G E T S B O R O N R E M O V A L Researchers at MIT are developing size-selective metal-organic frameworks to trap boric acid •One thing my group does is design new materials with the molecular precision to separate small molecules; they're called metal-organic frameworks (MOFs). In this project we are targeting boron removal, an unsolved challenge in membrane science. For agriculture, too much boron can be toxic to plants. In semi-conductors, it can ruin the entire process. You oœ en need a double-pass system or an exchange resin. These options are expensive from a capital and an energetics perspective. •If we could make a membrane that ac- complishes typical membrane performance for desalination, and add that special structure for removing boron, then we can have a one-pass RO. We talk in angstroms: boric acid has a diameter of approximately 5 angstrom and water is approximately 2.7 angstrom. We need something structured in a way that can reject that 5 angstrom- size boric acid, while still allowing that 2.7 water through. That's a very small scale; it's sub-nanometre in terms of design. •We have two approaches: composite, and inorganic … lm. The composite approach takes a polymer that we know operates well for RO as a support, and incorporates parti- cles of the size-selective MOFs. Alternative- ly we remove the polymer. That's a bigger challenge; to make something size-selective with the pure MOF material as … lm. •The key is getting the material. The next step will be to develop an actual process. The composite approach has a more straightforward route to commercialisa- tion. That has a few examples of practice in industry today for water puri… cation. The second approach; it would be a real step-change in performance if you can use just the active material. You have just the pure MOF accomplishing the entire separa- tion. That's a real game-changer if it can be done. There's no commercial example today of using mofs as pure materials. The project is led by Zachary Smith, professor of chemical engineering, Massachusetts Insti- tute of Technology (MIT), and spearheaded by Gang Han, research associate, MIT department of chemical engineering. It is an activity of Abdul Latif Jameel World Water and Food Security Lab at MIT What problem are you trying to solve? Why is boron removal so challenging? What are the diff erent ways of approaching this? Will the technology be marketable any time soon? Segmented monolithic membrane design Patented radium removal process The composite approach has a more straightforward route to commercialisa- tion. That has a few examples of practice in industry today for water puri… cation. The second approach; it would be a real step-change in performance if you can use just the active material. You have just the pure MOF accomplishing the entire separa- tion. That's a real game-changer if it can be done. There's no commercial example today of using mofs as pure materials. The project is led by Zachary Smith, professor of chemical engineering, Massachusetts Insti- tute of Technology (MIT), and spearheaded by Gang Han, research associate, MIT department of chemical engineering. It is an activity of Abdul Latif Jameel World Water and Food Security Lab at MIT soon?