Results of microplastic measurements from domestic wastewater treatment plants presented at the Academy
The Committee on Water Management of the Hungarian Academy of Sciences held its quarterly reporting meeting on April 3, 2024. At the meeting, special attention was paid to the latest research results on microplastics discharged through municipal wastewater. In this context, the RISK-MP project consortium - Eurofins Analytical Services Hungary Kft, the Hungarian University of Agricultural and Life Sciences, Institute of Aquaculture and Environmental Safety and the University of Pannonia - presented their first results collected during a survey of several Hungarian wastewater treatment plants.
Based on the results presented, it can be concluded that wastewater treatment plants are highly efficient in removing microplastics despite the fact that they are not designed to solve such problems. As a result of the processes involved in wastewater treatment, only 0.1-3% of the incoming microplastics enter the receiving surface waters with the treated water.
While some of the microplastics entering the treatment process with the water to be treated are removed with the screenings from the filtration in the mechanical treatment stage, a significant proportion of it enters the sludge generated during the wastewater treatment with the waste streams from the sand and grease traps, and it is important to take this into account in the subsequent utilization of the sludge.
The tests showed that nearly 80 particles per gram of dry matter could be detected in the sludge. Taking into account the nearly 170,000 tonnes of sewage sludge produced in Hungary each year, this represents about 13,000 billion particles, which is 1320 tonnes of microplastics by mass. The most commonly detected types of microplastics in sewage sludge were polyester (e.g., PET), polyethylene and polypropylene.
As a final step in the sample preparation, the concentrated sample is measured in an FTIR instrument by Eurofins experts.
It is important to stress that the primary opportunity to reduce the amount of microplastics released into the environment through treated wastewater and sewage sludge is at the point of wastewater generation, i.e., the less microplastics are released into our household wastewater, the less are released into the environment.
Therefore, the public's contribution to the prevention of microplastic pollution is of paramount importance. Ways to do this include avoiding the use of cosmetics, wipes and detergents containing microplastics, using filters on washing machines to remove microplastic fibers from washing and using non-plastic household utensils whenever possible.
The first regulations on the phasing out of microplastic ingredients have already appeared in European Community legislation and further legislation is in preparation to protect the environment.
The project 2020-1.1.2-PIACI-KFI-2021-00239 has been funded by the Ministry of Innovation and Technology through the National Research Development and Innovation Fund, under the Market-driven Research and Innovation Projects Support Programme.
