How water treatment drives higher-quality recycled plastics

Plastic recycling has a quality problem. An academic review paper from October 2025 found that global recycling rates remain stagnant at about 8%. The researchers identified that culprits like proteins and fats in leftover food, detergents, solvents and pesticides” make plastics harder to recycle effectively. 

New regulations are forcing facilities to increase their efforts in fighting contamination, which requires water treatment expertise. The Packaging and Packaging Waste Regulation (PPWR), which took effect in February 2025, mandates that PET beverage bottles contain at least 30% recycled content by 2030, rising to 65% by 2040. It was one of the tools the European Union implemented to achieve the goals set out in the European Green Deal and the Circular Economy Action Plan. The PPWR targets are set to design packaging for recirculation to increase the ease of recycling of these packages. However, the challenge remains in recycling packages that do not meet these criteria. By intensifying the washing of these materials, the quality of the recycled materials can be improved. 

Where quality is won or lost
The wash steps of the mechanical plastic recycling process — specifically the chemistry behind it — determine the quality of the recyclate. Loose residues come off easily enough with mechanical agitation. But labels, adhesives, inks and dyes, persistent deposits and embedded organic compounds resist mechanical shear forces even at temperatures of 80-95° Celsius and pH levels of 11 to 12. What stays behind in and on the flakes carries through to the pellets and ultimately into the recycled finished products. 

Residual fouling affects both the physical properties, like flexibility, stiffness, hardness and impact resistance, and the odor of recycled plastic. Consider car dashboards made from recycled polymer: If the plastic was not cleaned thoroughly during recycling, volatile organic compounds (VOCs) embedded in the material could release unpleasant odors when the dashboard heats up in the sun. Instead of a new-car smell, it emits the scent of a wastewater treatment plant. 

With the EU's recycled content mandates taking effect, the gap between high-quality and low-quality output is widening. PET bottle-to-bottle recycling is the highest standard. The material must be clean enough for the same beverage-contact application it originally served, meeting strict food safety legislation across different regions. Recyclers whose wash process delivers food-contact-grade output will command premium pricing. Those whose output falls short face shrinking options as regulations tighten.

Cleaning agents and foam control
The right cleaning chemistry makes a measurable difference in the hot wash operation. Veolia's ReCIRC™ program includes a cleaning agent designed specifically for the demanding conditions of mechanical plastic recycling, a pH-neutral blend of low-foaming surfactants and dispersants that dislodge adhesives, greases and food residues from the plastic surface and prevent redeposition thereof at temperatures up to 95° Celsius. Deployed during the hot wash, it targets the contaminants that mechanical forces alone cannot remove.

Low foamability is a critical feature. The vigorous stirring during the washing process generates significant foam from residual shampoos, detergents, food products and other surfactant-containing materials on the incoming plastics. Any cleaning agent that adds to the foam burden creates more problems than it solves. 

Foam control is a constant operational concern, and Veolia has several antifoam products available under the ReCIRC brand. Incoming material varies from batch to batch, and a load heavy with residual detergents or food products can overwhelm a system that was running smoothly the day before. Anti-foam products are a necessary part of any treatment program for mechanical recycling, working alongside cleaning agents to keep foam formation under control and the process running smoothly.

The full water picture
Cleaning chemistry addresses what happens during the wash. But what happens to the wash water over time, and how the wastewater stream is managed afterward, matters just as much for product quality and operating costs.

Wash water quality degrades with use. Contaminants accumulate, and if the water is not monitored and refreshed at the right intervals, recyclers end up washing plastic in increasingly dirty water. Used wash water passes through a dissolved air flotation (DAF) unit where solids are removed using coagulants and flocculants. From there, a portion of the water is recycled back into the wash process with fresh water added, while the rest flows to wastewater treatment. 

In-depth, continuous monitoring of washing operations and quality requires dedicated tools and expertise for interpreting the data. Veolia offers services and solutions grounded in decades of experience, and consistently delivers successful project outcomes for partners around the globe.

Veolia's approach focuses on building long-term relationships with its recycling customers to drive continuous improvement in sustainability and operational efficiency. At the heart of Veolia's strategy is the Value Generation Program (VGP), a comprehensive framework to help clients meet business goals and sustainability goals. Through the VGP, Veolia encourages open and proactive communication, ensures the health and safety of work teams and establishes "value projects" to drive ecological footprint and total cost of operations reduction. 

Once each project is completed and value certified by customers, Veolia rewards the teams involved to recognize and encourage their commitment to ecological transformation. This process ensures that Veolia remains closely aligned with its clients' evolving needs and challenges, allowing the development of tailored solutions that address both immediate concerns and long-term sustainability goals.

What comes next
Beyond mechanical recycling, chemical recycling through pyrolysis is an emerging pathway that can process plastics that mechanical methods cannot handle. Veolia is developing new product classes for advanced recycling applications, including pour point depressants, anti-foulants and oxidation stabilizers — all under the ReCIRC brand.

As regulatory pressure and market demand for recycled content continue to grow, recycling operations will need increasingly sophisticated water and chemical treatment to stay competitive — and a partner with decades of water expertise backed by the resources of a company that operates across the entire recycling value chain.

Contact Veolia to learn how the ReCIRC program can improve your recycling operation's efficiency, product quality and environmental performance.