This text is part of the special Research section
About 35% of microplastics in the oceans come from our washing machines. This invisible source of pollution could be partly avoided by filtering the water discharged by washing machines in Quebec cities, thanks to the work of a research team from Polytechnique Montréal.
As their name suggests, microplastics are pieces of larger objects that have degraded over time or become small in size during the manufacturing process. They largely come from ready-to-wear clothing made of synthetic fibers which, during machine washes, break down into smaller particles and end up in the waste water.
Dominique Claveau-Mallet, assistant professor in the Department of Civil, Geological and Mining Engineering at Polytechnique Montréal, has been interested in this question and potential solutions for several years. Mandated by the Group of Recommendations and Actions for a Better Environment (GRAME), his team analyzed the composition of residues from filters installed directly in the washing machine by around thirty households. Participants had to collect residue and report wash parameters on a tracking schedule, such as the cycle used or the percentage of machine fill.
The study found that an average Montreal household could divert up to 16 grams of plastics per year from the waste water path. City-wide, this corresponds to almost 13 tons of microplastics. However, the feedback questionnaires completed by households also allowed us to assess the barriers to the use and maintenance of the filter. How long does a washing step take? What problems are you having with the filter? Do you plan to continue using it after the experience? The results indicated a satisfaction rate of between 40% and 60%, depending on the questions.
In other words, if the technology works, it will not be easy to integrate into everyday life. “It’s very valuable information for taking the next step, because we’re in solution mode and that’s what makes citizen science projects so interesting,” comments Dominique Claveau-Mallet. We want to develop technologies that are easy to access and inexpensive, for everyone, not just for motivated people. »
Wastewater
To facilitate the process, the filters should be integrated directly into the washing machines at the time of manufacture. “We are submitting a political motion to the City of Montreal to ask the government to legislate in this direction,” continues the professor. While waiting for this request to materialize, she and her team are already looking into a solution on a larger scale.
Thanks to an Alliance grant from the Natural Sciences and Engineering Research Council of Canada (NSERC) and Mitacs Accelerate, his team will work to measure and characterize what goes in and out of our wastewater treatment plants. In other words, it will develop standardized analysis methods in order to better detect and quantify the presence of microplastics. ” THE timing is excellent for the project, because these cities are carrying out major rehabilitation work in the wastewater plants and are very proactive, adds Dominique Claveau-Mallet. If there are no regulations related to microplastics, we clearly see a desire to reduce them. »
With the collaboration of Claro and the cities of Repentigny, Longueuil and Laval, the project will rely on the expertise of Abdellah Ajji and Marie-Claude Heuzey, both professors in the Department of Chemical Engineering, as well as professors holders Benoit Barbeau and Yves Comeau, from the Department of Civil, Geological and Mining Engineering.
Rethink your consumption
The researcher and project director is optimistic about the growth of environmental awareness in modern societies. “We have to understand this problem [des microplastiques] in a global perspective and we will get there, we have no choice, ”she believes. Because, in addition to these exciting solutions, the most fundamental is to rethink one’s individual consumption of clothing.
“In order of priority, we should no longer buy clothes at all, and only reuse”, slice Dominique Claveau-Mallet. When this is not always possible, we then try to favor natural fibers such as hemp, and we avoid new by favoring second-hand clothes thanks to thrift stores.
This special content was produced by the Special Publications team of the Duty, pertaining to marketing. The drafting of Duty did not take part.