Separate waste collection on the University's campuses in Milan
How it works and how we can improve
Waste sorting on the Politecnico di Milano campuses follows the directives of the relevant municipalities, managed by the companies responsible for cleaning and maintaining the area. Each campus may therefore have different methods for municipal waste collection, but the goal remains the same: to prevent waste generation and maximize the quality and quantity of waste sorting, with a view to reducing environmental impacts. Effective waste sorting is a social responsibility, where everyone's commitment contributes to achieving sustainability goals.
How does waste sorting work?
To illustrate how waste sorting works, let's take the Città Studi Campus as an example, which has the highest attendance of students, faculty, and technical staff, as well as citizens who, for various reasons, frequent our university. On this campus, urban waste generated by the university is collected in three separate bins, each color-coded (blue, yellow, or black), each containing bags of the same color:
- Blue for Paper
- Yellow for Plastic and Metal
- Grey for Dry Waste (unsorted)
Once filled, each container is collected by the designated company and transported to an intermediate collection point on campus, designated as a Temporary Storage Facility, where certain types of waste produced on the Leonardo Campus are collected.
From there, a van from the same company transports the waste to the Campus recycling area, an area accessible only to authorized internal and external University personnel, near the Giuriati Sports Center. The area houses large-volume containers (20 m3) from AMSA – Azienda Milanese Servizi Ambientali, waste management company for the City of Milan.
Here, the operator sorts the waste based on the color of the bag. If significant anomalies are detected in the contents, such as a bag containing mixed waste (for example, paper mixed with aluminum cans), the entire bag is considered non-compliant and therefore disposed of as unsorted waste.
The containers are emptied by AMSA weekly according to the Municipality of Milan's separate waste collection schedule, and are then sent for recycling or recovery.
And what about glass? Does it differ across campuses?
Of course, glass is also separated, but its collection follows a different route: it is not transported to the Campus area like the other hamlets, but is transferred to special green wheeled containers that the operator displays on the street, on the designated days, to then be collected by AMSA according to the Separate Waste Collection Calendar.
Waste product analysis. What does it reveal? Can we improve?
To monitor the effectiveness of waste separation, Politecnico di Milano, in collaboration with AMSA, conducts product analyses of the waste fractions produced, in order to verify the quality of waste separation.
The latest analyses, conducted last December, found 46.5% of the dry waste sample to be recyclable, highlighting that waste separation is not occurring properly. Of this amount, 12% is plastic, 19.9% paper, and 14.6% compostable (currently without dedicated collection in the University's common areas).
The results of these latest analyses reveal that there is still room for improvement, and each of us can contribute by paying more attention to waste separation. The video, an integral part of this report, also highlights how the bags of dry waste (unsorted) collected during filming still contain a variety of recyclable waste. Therefore, greater attention and commitment to waste separation is needed from all of us.
The good news is that the tender for the installation of compostable waste bins was recently awarded, and they will be installed on Milan's campuses by the end of the year. This will further reduce the amount of compostable waste currently ending up in dry waste (unsorted).
And in the offices?
The topic of waste sorting is also well-regarded among technical and administrative staff. In several Central Administration offices, personal bins have already been eliminated and replaced with centralized areas consisting of three-way bins for the collection of paper, plastic/metal, and solid waste. This best practice is planned to be extended to other facilities.
Experimentation and innovation: the Nando project
To further improve waste management, Politecnico launched the Nando project, which introduces an innovative system for waste sorting. Thanks to Nando, each bin is equipped with smart sensors that allow for instant waste recognition, indicating which bin it should be placed in. Nando also allows for the quantitative and qualitative monitoring of disposed waste.
Measuring the amount of waste generated
Once the waste has been delivered to the ecological area of the Campus and properly sorted into the appropriate containers, it is collected by AMSA, which weighs it and provides the data to the University. This process makes it possible to measure the amount of waste generated that AMSA then collects and sends to the designated facilities (recycling and recovery plants).
This procedure allows for monitoring the trend of waste production and assessing its evolution in relation to the circular economy improvement initiatives implemented.
Below is the table containing data on the amount of the different waste fractions recorded at the Campus ecological area over a specific time period.
The solution, currently located at the Leonardo Campus, includes 12 collection stations with three bins each, equipped with tablets. The smart bins are currently located at the Leonardo Campus Library (Building 11), the Department of Physics Engineering (Building 8), the Infrastructure and Services Management Area (Buildings 1, 2, and 9), and the Campus Life Area (Building 3).
Some data relating to the quantities collected in 2024 at the Piazzola of Campus
| Waste | Weight(Kg) | |
| Paper | 15.000 | Data collected in the period Jul–Dec 2024 |
| Plastic/metal | 11.380 | Data collected in the period Jul–Dec 2024 |
| Dry waste | 40.350 | Data collected in the period Jul–Dec 2024 |
Finally, those wishing to learn more about waste separation at the University can consult the Guidelines for the Separate Collection of Packaging Waste and Other Municipal Waste at Universities. This document is the result of a collaboration between the National Packaging Consortium (CONAI) and the Network of Universities for Sustainable Development (RUS) - RUS's "Resources and Waste" Working Group, currently coordinated by the Politecnico di Milano.