Pine Bark as a Sustainable Solution for Antibiotic Removal from Wastewater

Researchers at the University of Oulu in Finland have developed a novel water treatment medium using modified pine bark to effectively remove antibiotics and pharmaceutical residues from wastewater. This initiative addresses the growing concern of antibiotic-resistant bacteria, which are exacerbated by pharmaceuticals entering the environment through wastewater streams. Antibiotics often reach wastewater from human consumption, hospital discharges, and improper disposal methods, such as flushing unused medications.

New Atlas

The traditional wastewater treatment processes are insufficient in eliminating all pharmaceutical contaminants, leading to their presence in local waterways and drinking water. The newly developed method utilizes pine bark, a byproduct of the forestry industry, which is abundant and cost-effective. By modifying this bark with magnetite (iron oxide), researchers have created a medium that can bind with and degrade various pharmaceuticals.

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In a four-month pilot project conducted at Oulu’s Taskila wastewater treatment plant, the modified pine bark demonstrated remarkable efficacy. It achieved approximately 99.7% removal of the antibiotic trimethoprim and around 93.7% for the antidepressant venlafaxine. The method also proved effective for other commonly used pharmaceuticals, including the painkiller ketoprofen and the blood pressure medication losartan. This high removal efficiency positions the pine bark solution as a viable alternative to traditional methods, such as activated carbon, which is more expensive and less environmentally friendly due to its production process.

Pine bark removes pharmaceutical residues from wastewater – an affordable way to keep antibiotics out of natureNew Atlas

Mahdiyeh Mohammadzadeh, the doctoral researcher leading the project, emphasized the potential for collaboration between wastewater treatment facilities and the forestry sector, stating, “I hope wastewater treatment plants and the forest sector will explore collaboration opportunities.” Professor Tiina Leiviskä, who supervised the thesis, noted that the simplicity and cost-effectiveness of producing a solid purification medium from pine bark are significant advantages, as high temperatures are not required for its modification.

Pine bark removes pharmaceutical residues from wastewater – an affordable way to keep antibiotics out of nature

While the results are promising, some experts caution that further research is needed to evaluate the long-term effectiveness and environmental impact of using modified pine bark on a larger scale. Concerns also exist regarding the potential for other contaminants not being addressed by this method.

Pine bark removes pharmaceutical residues from wastewater – an affordable way to keep antibiotics out of nature

The University of Oulu plans to continue exploring the use of natural materials, such as spruce bark tannins, to develop additional solutions for wastewater treatment. The findings from this research will be formally presented in a doctoral defense scheduled for January 23, 2026.

Pine bark removes pharmaceutical residues from wastewater – an affordable way to keep antibiotics out of nature

“Producing a solid purification medium from pine bark is cost-effective because high temperatures are not required and the modification is simple. The material can also be used to remove other contaminants.” — Tiina Leiviskä, Professor at Chemical Process Engineering Unit

Pine bark removes pharmaceutical residues from wastewater – an affordable way to keep antibiotics out of nature

“Everyone has the opportunity to influence the state of the environment. At home, never flush antibiotics into the sewer or throw them into mixed waste. In Finland, unused medicines can be returned to a pharmacy.” — Mahdiyeh Mohammadzadeh, Doctoral Researcher

Pine bark removes pharmaceutical residues from wastewater – an affordable way to keep antibiotics out of nature