Aerogel beads for seawater decontamination


Water pollution is among the most pressing environmental issues that society needs to face. When toxic substances reach water bodies, they degrade the water quality, posing a serious risk not only for the ecosystem but also to humankind. Among the many types of pollutants, there are inorganic species such as heavy metals like nickel, cadmium, lead, and others. Lead poisoning, for instance, has severe neurological effects like neuropathy, encephalopathy, and reduced intellectual capacity. Organic contaminants like solvents and oils can also cause health issues. Solvents like dichloromethane have adverse effects on the liver, kidneys, nervous system, and reproductive system.

Many technologies have been proposed and tested for water remediation. However, seawater decontamination is challenging because of the presence of ions which interfere with the decontamination process. Prof. Patrina Paraskevopoulou, Dr. Aikaterini Sakellari, Prof. Sotirios Karavoltsos, and colleagues from the National and Kapodistrian University of Athens, tested a new class of polyurea-crosslinked calcium-alginate (X-Ca-alginate) aerogel beads to decontaminate seawater from different types of pollutants. The beads are hydrophobic and highly porous, and their chemical identity was confirmed by solid-state magic angle spinning 13C NMR, available at the Slovenian CERIC Partner Facility at the National Institute of Chemistry in Ljubljana.

Graphical abstract of the paper (Credits to the authors of the paper)

Experimental results highlighted the capacity of X-Ca-alginate aerogels to adsorb lead, solvents and oils from seawater within a short time frame. The separation of organic solvents and oils from seawater is mostly complete within seconds. The beads also proved to be stable in seawater for at least a week and can be recycled and reused at least twice without a significant activity loss.

The tested aerogel showed impressive performance for seawater decontamination and is characterised by other relevant properties like ease of storage, deployment, reuse, and decontamination time. Therefore, the proposed technology can have an impact in a field that will be more and more relevant in the coming years.


Evaluation of polyurea-crosslinked alginate aerogels for seawater decontamination. Paraskevopoulou P., Raptopoulos G., Leontaridou F., Papastergiou M., Sakellari A., & Karavoltsos S., Gels, 2021.