A brand new different seawater desalination membrane to provide consuming water.
In accordance with the World Well being Group, about 785 million individuals world wide lack a clear supply of consuming water. Regardless of the huge quantity of water on Earth, most of it’s seawater and freshwater accounts for less than about 2.5% of the overall. One of many methods to offer clear consuming water is to desalinate seawater. The Korea Institute of Civil Engineering and Constructing Know-how (KICT) has introduced the event of a steady efficiency electrospun nanofiber membrane to show seawater into consuming water by membrane distillation course of.
Membrane wetting is probably the most difficult problem in membrane distillation. If a membrane displays wetting throughout membrane distillation operation, the membrane should be changed. Progressive membrane wetting has been particularly noticed for long-term operations. If a membrane will get totally wetted, the membrane results in inefficient membrane distillation efficiency, because the feed move via the membrane resulting in low-quality permeate.
A analysis crew in KICT, led by Dr. Yunchul Woo, has developed co-axial electrospun nanofiber membranes fabricated by another nano-technology, which is electrospinning. This new desalination expertise exhibits it has the potential to assist clear up the world’s freshwater scarcity. The developed expertise can stop wetting points and in addition enhance the long-term stability in membrane distillation course of. A 3-dimensional hierarchical construction ought to be shaped by the nanofibers within the membranes for greater floor roughness and therefore higher hydrophobicity.
The co-axial electrospinning approach is without doubt one of the most favorable and easy choices to manufacture membranes with three-dimensional hierarchical constructions. Dr. Woo’s analysis crew used poly(vinylidene fluoride-co-hexafluoropropylene) because the core and silica aerogel combined with a low focus of the polymer because the sheath to provide a co-axial composite membrane and acquire a superhydrophobic membrane floor. In truth, silica aerogel exhibited a a lot decrease thermal conductivity in contrast with that of standard polymers, which led to elevated water vapor flux throughout the membrane distillation course of as a result of a discount of conductive warmth losses.
Many of the research utilizing electrospun nanofiber membranes in membrane distillation purposes operated for lower than 50 hours though they exhibited a excessive water vapor flux efficiency. Quite the opposite, Dr. Woo’s analysis crew utilized the membrane distillation course of utilizing the fabricated co-axial electrospun nanofiber membrane for 30 days, which is 1 month.
The co-axial electrospun nanofiber membrane carried out a 99.99% salt rejection for 1 month. Based mostly on the outcomes, the membrane operated nicely with out wetting and fouling points, as a result of its low sliding angle and thermal conductivity properties. Temperature polarization is without doubt one of the vital drawbacks in membrane distillation. It could lower water vapor flux efficiency throughout membrane distillation operation as a result of conductive warmth losses. The membrane is appropriate for long-term membrane distillation purposes because it possesses a number of necessary traits corresponding to, low sliding angle, low thermal conductivity, avoiding temperature polarization, and lowered wetting and fouling issues while sustaining super-saturated excessive water vapor flux efficiency.
Dr. Woo’s analysis crew famous that it’s extra necessary to have a steady course of than a excessive water vapor flux efficiency in a commercially out there membrane distillation course of. Dr. Woo mentioned that “the co-axial electrospun nanofiber membrane have sturdy potential for the therapy of seawater options with out affected by wetting points and would be the applicable membrane for pilot-scale and real-scale membrane distillation purposes.”
Reference: “Co-axially electrospun superhydrophobic nanofiber membranes with 3D-hierarchically structured floor for desalination by long-term membrane distillation” by Yun Chul Woo, Minwei Yao, Wang-Geun Shim, Youngjin Kim, Leonard D. Tijing, Bumsuk Jung, Seung-Hyun Kim and Ho Kyong Shon, 4 January 2021, Journal of Membrane Science.
The Korea Institute of Civil Engineering and Constructing Know-how (KICT) is a government-sponsored analysis institute established to contribute to the event of Korea’s building trade and nationwide financial progress by creating supply and sensible expertise within the fields of building and nationwide land administration.
This analysis was supported by an inner grant (20200543-001) from the KICT, Republic of Korea. The outcomes of this undertaking have been revealed within the worldwide journal, Journal of Membrane Science, a famend worldwide journal within the polymer science area (IF: 7.183 and Rank #3 of the JCR class) in April 2021.