Using a combination of techniques, to remove medicine residues from effluent
More and more medicine residues end up in nature, especially in waterways such as rivers. The long-term consequences for our health are unknown. Wageningen University & Research investigates how advanced purification technologies can be combined to effectively monitor and extract medicine residues from the water. They simultaneously remove bacteria that are resistant to commonly used antibiotics.
More and more pharmaceutical waste and residues of the medicines we use, end up via our urine and faeces in effluent. “Regular treatment methods cannot remove all these medicine residues”, explains researcher Tania Mubita Zambrano of Wageningen University & Research. This contaminated water flows through the sewage purification plants to ditches, rivers and lakes, which are also the sources of our potable water. “Some chemicals are extremely persistent. These remain in the water even after purification processes and eventually accumulate in the environment”, says Mubita Zambrano.
This article appeared in TO2MORROW, the magazine of the TO2 Federation. This organization publishes this impact report once a year, featuring the results of research and collaboration among the five TO2 institutes: Deltares, MARIN, NLR, TNO, and WUR.
Medicine residues more often
The water boards are increasingly discovering medicine residues in the water, even after treatment in the sewage purification plants where the effluent is purified. These include residues of various types of antibiotics, the commonly used pain relievers Ibuprofen and Carbamazepine, a medicine for epilepsy and manic-depressive symptoms.
The precise effects on human and animal health of medicine residues in effluent are still unknown, although research has shown that some medicines residues disrupt the reproduction of fish and change their behaviour. “What exactly happens when the fish are then eaten by other animals or humans, is unclear. Perhaps these substances are not harmful to us, but then again, perhaps they are. We simply do not know the long-term effects. That is why it is all the more important to extract these substances from the water”, Mubita Zambrano emphasises.
Research in practice
With her colleagues, she jointly conducts research into the effectiveness of three innovative technologies, in conjunction with a water board, a pharmaceutical company, and technology suppliers. The technologies remove medicine residues as well as harmful bacteria that are now resistant to certain commonly used antibiotics. “This will enable us to work simultaneously on reducing antibiotic resistance in the water”, explains Mubita Zambrano.
The researchers focus on thirteen medicines and have taken samples of the effluent from four hospitals and two healthcare institutes spread across the Netherlands. “Hospitals and healthcare institutes are ideally suited locations for testing, as they are a source of emissions of large quantities of medicine residues into the sewerage system”, says Mubita Zambrano. In the laboratory, the researchers study the effectiveness of the three different technologies to remove the medicine residues and bacteria.
Together with the HAN University of Applied Sciences, the researchers are also working on measuring systems that can be placed in the effluent at hospitals to continuously detect and monitor concentrations of specific medicine residues and antibiotic-resistant bacteria.
Purification technologies
The first technology, nanofiltration, uses a porous barrier that allows water to pass through and retains some medicine residues. The second technology, UV light in combination with hydrogen peroxide, tackles the substances that pass through the barrier anyway. This technique breaks down the substances into smaller molecules, which can then undergo further degradation processes, possibly reducing their impact on the environment. The third technology, plasma water, breaks down the residues using electricity and without the addition of chemicals.
The use of a combination of different technologies can be very effective.
Research has shown that the combination of these technologies is more effective than the purification methods currently in use. Mubita Zambrano: “A single technology is not enough to remove the medicine residues. The use of a combination of different technologies can be very effective. However, the methods require considerable investments and energy.” She continues: “I hope that public authorities will invest in introducing these technological solutions. Treating effluent at its source is one way of reducing the spread of persistent waste substances in water sources. It is just as important to make people aware of the fact that all the medicines we take, end up in our waste water. If this is not treated properly, it can accumulate in our living environment.