A plant-based metal organic framework (MOF) has been demonstrated by an international research group to efficiently capture and degrade pharmaceutical molecules found in local municipal wastewater.

The porous MOFs described in Nature Water were synthesized using ellagic acid, a naturally occurringThe crystal structure of the MOF; zirconium units are shown as blue polyhedral. Source: Nat Water (2023). https://doi.org/10.1038/s44221-023-00070-z molecule found in plants, derived from pomegranate peel or tree bark. Zirconium cations are added to the sustainably sourced MOF to promote chemical stability and maintain pore structure.

Application of the porous MOFs to water that had already been purified at a local wastewater treatment facility revealed that the new material removed many of the pharmaceutical pollutants that had not been fully eliminated. In addition to capturing these hazardous constituents, the MOFs were observed to break down pollutants using light. Laboratory-scale tests with select pharmaceutical compounds at higher concentrations also indicated that the MOFs simultaneously served as both an adsorbent and a photocatalyst of organic contaminants.

The cationic MOFs developed and tested by researchers from Stockholm University (Sweden), IMDEA Energy (Spain), Uppsala University (Sweden), Universidad Nacional Autónoma de México and IVL Swedish Environmental Research Institute may be of interest for the selective capture of anionic emerging organic contaminants.