According to the World Health Organization, about 785 million people around the world lack a clean source of drinking water. Despite the vast amount of water on Earth, most of it is seawater and freshwater accounts for only about 2.5% of the total. One of the ways to provide clean drinking water is to desalinate seawater. The Korea Institute of Civil Engineering and Building Technology (KICT) has announced the development of a stable performance electrospun nanofiber membrane to turn seawater into drinking water by membrane distillation process.:

Membrane wetting is the most challenging issue in membrane distillation. If a membrane exhibits wetting during membrane distillation operation, the membrane must be replaced. Progressive membrane wetting has been especially observed for long-term operations.

If a membrane gets fully wetted, the membrane leads to inefficient membrane distillation performance, as the feed flow through the membrane leading to low-quality permeate.

A research team in KICT, led by Dr. Yunchul Woo, has developed co-axial electrospun nanofiber membranes fabricated by an alternative nano-technology, which is electrospinning. This new desalination technology shows it has the potential to help solve the world’s freshwater shortage. The developed technology can prevent wetting issues and also improve the long-term stability in membrane distillation process. A three-dimensional hierarchical structure should be formed by the nanofibers in the membranes for higher surface roughness and hence better hydrophobicity.

The co-axial electrospinning technique is one of the most favorable and simple options to fabricate membranes with three-dimensional hierarchical structures. Dr. Woo’s research team used poly(vinylidene fluoride-co-hexafluoropropylene) as the core and silica aerogel mixed with a low concentration of the polymer as the sheath to produce a co-axial composite membrane and obtain a superhydrophobic membrane surface. In fact, silica aerogel exhibited a much lower thermal conductivity compared with that of conventional polymers, which led to increased water vapor flux during the membrane distillation process due to a reduction of conductive heat losses.

Most of the studies using electrospun nanofiber membranes in membrane distillation applications operated for less than 50 hours although they exhibited a high-water vapor flux performance. On the contrary, Dr. Woo’s research team applied the membrane distillation process using the fabricated co-axial electrospun nanofiber membrane for 30 days, which is 1 month.

The co-axial electrospun nanofiber membrane performed a 99.99% salt rejection for 1 month. Based on the results, the membrane operated well without wetting and fouling issues, due to its low sliding angle and thermal conductivity properties.

The co-axial electrospun nanofiber membrane performed a 99.99% salt rejection for 1 month. Based on the results, the membrane operated well without wetting and fouling issues, due to its low sliding angle and thermal conductivity properties.

Temperature polarization is one of the significant drawbacks in membrane distillation. It can decrease water vapor flux performance during membrane distillation operation due to conductive heat losses. The membrane is suitable for long-term membrane distillation applications as it possesses several important characteristics such as, low sliding angle, low thermal conductivity, avoiding temperature polarization, and reduced wetting and fouling problems whilst maintaining super-saturated high water vapor flux performance.

Dr. Woo’s research team noted that it is more important to have a stable process than a high-water vapor flux performance in a commercially available membrane distillation process. Dr. Woo said that “the co-axial electrospun nanofiber membrane have strong potential for the treatment of seawater solutions without suffering from wetting issues and may be the appropriate membrane for pilot-scale and real-scale membrane distillation applications.”

Reference:
https://www.chemeurope.com/en/news/1171742/making-seawater-drinkable-in-minutes.html

More News
ECHA Adds Five Hazardous Chemicals To PIC
News · 08/09/2023

The European Chemicals Agency (ECHA) has amended the Prior Informed Consent (PIC) Regulation, EU 64/2012, to add 27 pesticides and eight industrial chemicals into Annex I, bringing the total to 295. As a result, EU exporters are now required to notify their intentions to export them from 1 November onwards.

READ MORE
Global Custom Synthesis & Manufacturing: Escalating Demand for Specialty Chemicals Drives Growth
News · 04/09/2023

The global custom synthesis and manufacturing market was valued at US$271.33 billion in 2022. The market value is expected to reach US$474.94 billion by 2028.

READ MORE
4 key Trends Reshaping Ocean freight Industry in 2023
News · 04/04/2023

The ocean freight industry is undergoing a massive transformation, as the technology and supply chain management tools are being improved by the day, impacting ocean freight rates.

READ MORE
What do China’s data export regulations mean for its trade competitiveness?
News · 13/12/2022

In the second half of 2022, China unveiled the details of its data export regulations, providing further explanations to its existing laws and regulations on data.

READ MORE
Energy Crisis: The EU Chemical Industry Is Reaching Breaking Point
News · 11/11/2022

The current energy crisis has reached an unsustainable level for the European chemical industry. For the first time ever, the EU imports more chemicals than it exports, both in volume and value, resulting in a trade deficit of € 5.6 bn for the first half of 2022.

READ MORE
European Union proposes to add two new hazard classes to EU CLP regulation for endocrine disruptors (EDCs)
News · 17/10/2022

Endocrine Disrupting Chemicals (also referred to as hormone disruptors or EDCs) are synthetic chemicals that are not produced by the human body and that disrupt the normal functioning of humans and animals.

READ MORE
The Shipping Industry in a downward spiral
News · 03/10/2022

The shipping industry is now returning to normality and is in a downward spiral. The cost of shipping goods from China has slumped to the lowest level in more than two years as the world economy stumbles, dimming prospects for container carriers that turned in record profits during the pandemic.

READ MORE
Global Freight Situation
News · 08/09/2022

No precipitous plunge in container shipping rates, just ‘orderly’ decline.

READ MORE
3 Key Insights into the Global Food and Beverage Market
News · 02/08/2022

The global food and beverage market size is expected to grow from $5.8 trillion in 2021 to $6.4 trillion in 2022 at a growth rate of 9.7%. The food and beverage market size is expected to grow to $8.9 trillion in 2026 at a compound annual growth rate of 8.7%.

READ MORE