Metal adsorption

Metals occur in all-natural waters as well as most waters from human activities e.g. industrial processes and wastewaters. The ability to remove excess metals from waters is important for example in water purification from toxic heavy metals or in metal manufacturing. There are several methods to collect metals from aqueous solutions but it is challenging to extract metals that have low concentrations especially when a specific metal needs to be selectively removed from a mixture of dissolved metals.

We are developing new nanostructured hybrid materials for selective adsorption of metals from aqueous solutions. The materials are based on nanoporous materials such as porous silicon and silicon carbide functionalized with metal chelating functional groups. The aim is to develop materials that are selective toward certain metals, can reversibly adsorb and desorb the metals and can be reused for tens or hundreds of times without significantly altering its properties.

The above graph shows how scandium can be selectively extracted with the develop hybrid material from a solution with several metals in equal concentration. The relative concentration of Sc is increased more than 3-fold while the relative concentrations of other metals decrease.

The graph shows how the hybrid material can be used repeatedly to adsorb and desorb metals (in this case scandium). The performance of the material is not significantly altered even after 50 adsorption/desorption cycles.

Technology originating from our group is being commercialized by a spin-off company 3AWater. They offer a portable analysis technique to measure the low concentration of metals on-site in real-time.