Every time a person takes medication, a small amount of it ends up in the wastewater via the urine. It also reaches surface water and even drinking water (in small concentrations). Every year, about 140 tons of medicine residues are involved, with all kinds of consequences for fish and other animals and plants that live in and around the water.
Micro-organisms can clean the waste water and break down medicine residues. “We already knew that certain substances such as paracetamol are removed by bacteria,” says microbiologist Ana Rios-Miguel, who will be awarded her doctorate at Radboud University in Nijmegen on 14 September for research into the microbial removal of medicines under the conditions of a wastewater treatment plant. “How the process works and which mechanisms underlie this process were still unknown.”
Nano sieves remove dirty particles from waste water
On Tuesday 17 May, the UT opened a membrane test installation at the Enschede sewage treatment plant.
Eat
During research in the lab, Rios-Miguel looked at samples of waste water to which paracetamol had been added. She then studied how bacteria ‘eat up’ the active substances from paracetamol. “We have not added anything new, but we have investigated what exactly is happening.”
Genetic Elements
For example, Rios-Miguel discovered that higher drug concentrations in the wastewater increase the removal rate. She also found which genetic elements are responsible for the conversion of paracetamol in wastewater treatment plants. This knowledge will make it possible in the future to use micro-organisms in a more targeted way in wastewater treatment.
There are currently two important methods for removing drug residues from sewage water, namely with ozone and UV technology and activated carbon (powdered carbon). Medication residues attach themselves to the activated carbon and thus partially disappear from the water. Rios-Miguel: “The disadvantage of activated carbon is that it is expensive and has a large CO2 footprint. But micro-organisms can improve and prolong the effect of the activated carbon, allowing you to remove medicine residues more effectively and environmentally friendly.”
Research into the effect of micro-organisms in waste water will be continued at Nijmegen University. Rios-Miguel wants to use her research to come up with solutions for wastewater purification in practice.