Plastic Metal Technology


PMT is the leading French producer of biodiscs. The compact biological waste water treatment plants by PMT have been exported worldwide since 1998. Thanks to their good landscape integration, to their odorless biomass and their simplicity of exploitation, the biodiscs have been recognized as the reference technology for the small and medium sized waste water plants.

History of the biodiscs and birth of PMT

Biodiscs were introduced in Europe at the end of 1960’s and have quickly seduced the market by their simplicity, rusticity, robustness, the reliability of their fixed biomass culture, and the cost efficiency of their operation. 

However, after a few years, it appeared that this first generation of equipment installed was mechanically not strong enough because of conception shortcomings (disks in expanded polystyrene which were too frail, porous discs which were subject to unbalanced biomass growth, tear and wear on the chains and drive rings, uprooting of gear motors seals, wear of overloaded and greaseless bearings, rupture of the welded flanges on the axis and tubes, hollow shafts buckling leading to problems in the biodiscs positioning, corrosion). Because of these structural defects, the technology almost disappeared in the 1980’s. It was necessary to wait for 15 years and the arrival of new, more robust units from Germany to be once again prescribed in the public tenders.

PMT was founded in 1998 in Savoie. The success of its treatment units designed in tough rigid plastic polypropylene, coupled to a stainless steel structure and equipped with a full stainless steel shaft has enabled a quick development of the company. To support this quick development, PMT has created a subsidiary in Germany in 2000.

Accumulating the successful references, PMT expended and in 2008, the family owned company was acquired by the Veolia group. By keeping its original structure and adding its international network, the Veolia group has allowed PMT to address ever more distant markets.

Find out more about biodiscs Ecodisk®

PMT exports to international projects


The treatment of the effluent from the small and medium communities requires solutions that are robust, economical, easy-to-operate, with a low sensibility to load and hydraulic variations. This is especially true for the smallest communities. 

The biodiscs process is the perfect answer to these constraints. In particular, it is not necessary to hire an electrician or a specialist in water treatment to operate the Ecodisk® treatment units. A simple weekly visite is enough to guarantee a good operation.

Various processes have been tried (trickling, lagoons, sand filter…) and recommended for the small and medium capacity waste water treatment plants. Yet today, the latest return of experience have shown recurring malfunctions, sometimes of a worrying scale (cleaning problems, sludge evacuation, insufficient treatment rates, clogging, odors…) on these technologies.

The fixed culture biodiscs of the brand Ecodisk® have been commercialized by PMT since 1998. Their modular conception by blocks allows for a proper design for each given project. This solution, which is especially adequate to solve the issue of the waste water treatment, integrates perfectly in the landscape. The unit tanks are reinforced and can be buried without the need for concrete reinforcements or protections. It should be noted that one of the biggest advantage of this fixed culture process is the absence of odor!


Among the modular range of Ecodisk®, you should be able to find one for the type of treatment you need:

  • classic Ecodisk® biodiscs for the treatment of carbon and nitrogen pollutions (nitrification);
  • Ecodisk® Denit biodiscs with airproof covers for advanced treatment of nitrogen through denitrification;
  • PMT lamella settlers, stand-alone or coupled to biodiscs, for wastewater or rainwater clarification;
  • Ecodisk Filter® series with drumfilters coupled to the biodiscs shafts for an advanced secondary clarification 
  • Poligreen® product range for the combined treatment of total suspended solids and residual phosphorus;
  • Ecodisk® M design for an advanced outlet filtration in combination with sludge storage on reed beds.
range ecodisk PMT

Ecodisk® solutions are available:

  • for waste water treatment units with capacities from 100 to 10 000 people equivalent;
  • for purchase or rental by the month or by the years;
  • in large diameters with discs up to 4 meters in diameter for highly compact solutions inside buildings;
  • with options such as the color of the covers or the installation of flowmeters and antifreeze systems…

The PMT network

PMT is capable, with its own teams, to support you on site within the best delay anywhere in France, Germany and even Europe and internationally. Should it be for an installation, a commissioning or a control and maintenance visit, you can trust our small but dynamic team to serve you well.

If we are able to answer your needs in the best delays, that’s because we work with a network of international distributors who are capable of providing you with the requested technical support for the good delivery of your projects.

Thanks to this proximity and reactivity, the PMT equipment are being exported further and further. We are providing solutions to hotels as well as municipalities, isolated living bases, hospitals, residencies, schools and universities …

Finally, if our biodiscs solutions were not the best fitted to your project, we would request the support from other divisions of the Veolia group. In any case, if you contact us, you are certain to obtain a technical solution to your project.