Second part — Notes from the Scientific and informative day promoted by the Microplastics on Human Health Committee with the municipality of Milan
After Monday’s post on research and scenarios, we turn to a more urgent question: are there realistic solutions to micro and nanoplastics?
This is the second part of the second annual outreach conference on micro- and nanoplastics, organised by the Microplastics on Human Health Committee in collaboration with the Municipality of Milan. (You can read part. 1 here).
Exploring ideas and solutions to micro and nanoplastics.
The recovery of micro- and nanoplastics in biomethane production
Alessandro Daneu, Environmental Engineer
He focused on organic wastewater treatment through anaerobic digestion for biogas and biomethane production. This is not only an excellent example of circular economy but also — with appropriate process modifications — a potential solution to reduce the dispersion of micro- and nanoplastics while simultaneously using them to increase biomethane production.
These solutions are currently being tested and patented, further confirmed by collaboration with Tongji University in Shanghai.
The starting problem is simple:
We are immersed in plastic. Ultimately, it has to go somewhere.
Today, we recover large, visible plastic at collection centres. In some European countries, every plastic number has its own container. When plastic is mixed, separation systems exist — but recovery is very difficult. The only plastic easily recoverable is PET (bottles).
Italy is at the forefront of PET recovery, recovering more than 50% — higher than the European requirement.
Plastics that aren’t recovered end up in waste-to-energy plants. Since they’re a petroleum derivative, combustion is the most appropriate use.
The real problem is micro- and nanoplastics — about which we know little.
Plastics from organic waste most easily enter the water cycle. The challenge is separating plastics without shredding them, as was once done.
Biomethane as an opportunity for Europe:
It represents the valorisation of waste. These are molecules that, if recovered, do not enter the environment. The nitrogen contained in organic proteins is transformed into ammonia, which can create environmental problems. Here, ammonia recovery is also possible.
From an energy perspective, biomethane replaces natural methane — reducing foreign dependence, creating a domestic product, and providing clean fuel recovered from recycling.
Today, many freight trucks are methane-powered, and a large portion run on biomethane.
Energy is recovered and sold. Fertilisers can be made. Ammonia can be recovered as bioammonia. By-products that can be reused.
FMSW (municipal organic waste). Initial separation is important because all sorts of things end up in the organic waste. The recycling process does not consume external water.
Debunking some myths:
• Separating macroplastics does not eliminate microplastics and nanoplastics — they still end up in our waters.
• The only way to intercept them is in purifiers, wastewater, and water treatment processes.
• Biodegradable or compostable plastic does not solve the problem. We get microplastics and nanoplastics anyway.
• The downstream purifier does not solve the problem on its own unless appropriate treatment policies are implemented.
• Anaerobic digestion does not solve the entire problem — in fact, it could create one due to ammonia.
What can we do: solutions to micro and nanoplastics
PHAs and microplastics: sustainable solutions for agriculture and design
Eligio Martini, Chemical Engineer and Maip group president
The accumulation of microplastics in agricultural soils is an emerging problem threatening soil fertility, crop health, and food security. Conventional plastics used in agriculture — mulch films, greenhouse films, irrigation materials — fragment and persist in the environment for a long time.
Enter PHAs (polyhydroxyalkanoates): bioplastics of microbial origin, completely biodegradable in soil. A promising alternative.
The confusion around “bioplastics”
The term isn’t accurate. “Bioplastics” means everything:
- Some are of natural origin (not from oil).
- Some are biodegradable in specific conditions.
- But not all bioplastics are biodegradable.
- Some bioplastics come from oil and are biodegradable.
Real bioplastics are both natural in origin and biodegradable.
What is PHA?
A natural polymer. Exists in nature. Biodegradable.
Forms through fermentation — a natural process. Transformation of a polymer into biomass, water, and carbon dioxide.
PHA is a family of polymers. Fermenters are used to produce it, but the process is natural.
Polyester is a large family of materials that can be more or less harmful. Polyester is the chemical characteristic of the material. The chemical structure makes it a polyester, but there are different kinds of polyesters.
Why PHA matters:
Unlike PLA (which is not biodegradable everywhere and lasts like traditional plastic), PHA is biodegradable under all conditions—controlled or not by man.
Truly biodegradable materials:
- Pure cellulose (paper, not wood)
- Rice starch
- PHA
PHA is the only natural material that can be processed like plastic but is not plastic. It releases no microplastics. Nothing toxic for the environment.
A striking statistic:
All the plastic islands we see in the seas? Only 2% of the plastic present in the water. PHA would help solve the rest.
Applications are vast:
Pens, cosmetics, packaging, bioremediation of the seas, agriculture — where plastic gets discarded and never collected.
So why aren’t we using PHA everywhere?
It’s called “the sleeping giant” — quite unknown, perhaps to emphasise its potential but limited use. It is more expensive than plastic, so it’s used for high-value items.
The challenge: passing the concept that even if it costs more, the long-term positive effects are worth it.
Note: The MAIP Group (European) is one of the few producers of PHA.
The microplastic-free lamp and fashion from organic farming and certified forests
Natasha Calandrino Van Kleef and Carlo Covini — Sustainable design experts, NKV and Lenzing
Natasha presented the design of a design object — the “Sibilla” lamp prototype — entirely made with a process that produces no microplastics throughout the entire product cycle.
Together with Carlo Covini (Lenzing manager), she also illustrated a virtuous example of completely natural clothing, including all its components and therefore certifiable: “Garments from Organic Farming and Certified Forests.”
Key distinction: biodegradable vs. compostable
- Biodegradable: a natural process (light, water, air)
- Compostable: an industrial process
This distinction forms the backdrop to the new NKV Fashion & Lenzing project — the result of years of research into microplastic pollution in fashion.
What they discussed:
Garments made from 100% hemp or 100% organic cotton, both GOTS (Global Organic Textile Standard) certified.
Sewn with innovative TENCEL™ Lyocell sewing thread from certified forests.
The bigger picture:
Cellulosic fibres make up only 6% of the market.
Meanwhile, synthetic fibre production is increasing.
Biochar and innovative solutions
Dalia Benefatto — Sustainable economy expert
She explained the nature of biochar: a vegetable carbon obtained from the pyrolysis of agricultural waste and organic residues.
Why biochar is promising:
The production process has particularly attractive environmental characteristics — it co-produces renewable energy and is carbon-negative.
But most importantly, biochar is a prime tool for removing micro- and nanoplastics from the environment.
Milestones achieved and future potential
Among the advantages of biochar: its use as a carbon-negative pigment for dyeing — an eco-friendly and functional alternative.
The analysis addresses pressing challenges, exploring its potential effectiveness in mitigating PFAS. An experimental study is proposed on cotton-polyester blend fabrics, with the aim of transforming them into new by-products while eliminating the release of microplastics.
Key concept: Return economy
- Waste as a resource
- Waste valorisation
And: biochar removes CO₂ from the atmosphere.
Innovation and process in hospitals
Elena Bottinelli — Director, Villa Erbosa – San Donato group
She emphasised that those working in the healthcare sector cannot ignore the One Health approach — the interconnection between human health, animal health, and environmental health.
The key question:
How are hospitals implementing initiatives to reduce their environmental impact?
The scale of the problem:
25% of hospital waste is plastic.
The challenge:
Reducing plastic consumption while maintaining cost-effectiveness and sterility — guaranteed by the use of disposable products.
The proposal:
Process innovations that combine plastic reduction with organisational efficiency, resulting in positive impacts on overall sustainability. Evidence from best practices.
Solutions to micro and nanoplastics — Final thoughts
So yes, solutions to micro and nanoplastics exist.
The question is whether we — citizens, institutions, industries — are willing to adopt them before the system reaches its limits.
Time is not on our side.
From biomethane recovery to PHA, from biochar to circular processes, the ideas are there. But they remain fragmented — often expensive, often limited in scale, often carried forward by the same actors.
And this is where a familiar discomfort returns.
When we hear about certifications, “certified forests”, biodegradable materials, something doesn’t fully settle. Not because these solutions are false. But because we have learned how easily they can be absorbed into narratives that promise change without transforming the system.
Greenwashing wasn’t named here either.
But again, it lingered.
In sectors like fashion, the gap is still evident. Beyond pilot projects and virtuous examples, the structural issues remain: overproduction, waste, and a system that continues to generate the problem faster than it can solve it.
So the question is no longer whether solutions exist.
It is whether we are ready to recognise the difference between solutions and stories — and who benefits when we confuse the two.