New pine bark filter removes over 90% of drug traces from wastewater

Researchers at the University of Oulu in Finland have developed an innovative, low-cost water treatment method using iron-modified pine bark to remove pharmaceutical residues from wastewater. This sustainable purification medium leverages pine bark’s natural polyphenolic compounds, enhanced with magnetite (iron oxide), to effectively capture a wide range of drugs—including antibiotics like trimethoprim and antidepressants such as venlafaxine—with removal rates exceeding 90%. The magnetic properties of the modified bark allow easy separation from water after treatment, offering a practical and environmentally friendly alternative to conventional methods like activated carbon and ozonation, which are energy-intensive and costly. The research team tested the material over four months at a wastewater treatment plant, targeting post-treatment water where drug residues, though low, still pose ecological risks. Their findings demonstrated near-complete elimination of certain pharmaceuticals, while advanced cobalt-magnetite composites showed potential for breaking down more resilient antibiotics like levofloxacin. This approach aligns with circular economy principles by utilizing abundant forestry by