Techno Business Units

  • PMT


Compact wastewater treatment solutions

Ecodisk® - The Ecological solution for domestic wastewater treatment plants, from 100 to 10,000 Population Equivalent

The Ecodisk® Biodiscs

The treatment of the effluent from the small communities requires solutions that are rustic, 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 visual check 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 ECOSISK® 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 since 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 odors!


The various types of installations offered by PMT

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


  • biodiscs for the treatment of carbon pollution, in combination with a lamella settler if necessary
  • biodiscs for the treatment of carbon and nitrogen pollution (nitrification)
  • denitrifications with biodiscs (ECODISK® DENIT product range with an airproof cover)
  • treatment of the TSS and residual Phosphorus with the Poligreen® product range
  • advanced outlet filtration with the ECODISK M® design
  • stand-alone lamella settlers for wastewater or rainwater
  • drumfilters coupled to the biodiscs shafts in the ECODISK FILTER® product range
  • renting of waste water treatment units in various sizes, from one month to several years
  • supply and installation of large diameter discs solutions, up to 4m of diameter, for highly compact units inside buildings
  • customization with options such as the color of the covers or the installation of flowmeters …

PMT is capable, with its own teams, to support you on site within the best delay anywhere in France, Germany and even Europe. 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.


The PMT Network

However, our small team cannot be reactive everywhere in the world. And yet, we are able to answer your needs in the best delays thanks to our network of international distributors who will be capable of providing you with the requested technical support for the good delivery of your projects.

Thanks to this proximity and reactivity, the PMT equipments 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.



Grischow - Germany

  • Capacity: 275 PE
  • Treatment process line: Bar screen, settler digester, EcodiskTM, secondary clarification
  • Disk surface area: 2,080 m²

Wissant - France

  • Capacity: 4,400 PE
  • Treatment process line: Bar screen, rotary sieve, storm basin, Ø 3.80 m disks, Hydrotech™ drum filters, UV disinfection and reed beds
  • Disk surface area: 41,300 m²

Roncey - France

  • Capacity: 800 PE
  • Treatment process line: Bar screen, primary settlers, EcodiskTM Filter, lagoon & drying bed
  • Disk surface area: 4,680 m²

Rathewalde - Germany

  • Capacity: 1,000 PE
  • Treatment process line: Existing plant rehabilitation - Ø 3.90 m disks installed in existing concrete tanks
  • Disk surface area: 7,645 m²

Freissinière - France

  • Capacity: 1,100 PE
  • Treatment process line: Sieve, Ø 3.70 m disks installed in concrete tanks, Hydrotech™ drumfilter, thickener and dewatering table
  • Disk surface area: 8,560 m²

Oyster Pond - Saint Martin

  • Capacity: 1,100 PE
  • Treatment process line: Plant near houses with rotary sieve, three EcodiskTM Filter lines and a sludge silo
  • Disk surface area: 7,500 m²

Pizay - France

  • Capacity: 1,000 PE
  • Treatment process line: Bar screen, Settler digester, EcodiskTM with lamellar settling tank
  • Disk surface area: 5,370 m²

Residence Atelemo - New Caledonia

  • Capacity: 320 PE
  • Treatment process line: Plant near houses with a settler digester and two EcodiskTM lines with lamellar settling tank
  • Disk surface area: 2,660 m²

Naviti Resort - Fiji Islands

  • Capacity: 1,200 PE
  • Treatment process line : "Settler digester" and two EcodiskTM lines with lamellar settling tank
  • Disk surface area : 5,100 m²

Operating Principle

Ecodisk® is integrated in a treatment process line with three main stages.


Provided by:


  • Either a manual or automated bar screen or sieve;
  • Or a settler digester (or a compartmented settling tank) providing screening, grit removal, degreasing, settleable material removal, storage and digestion of excess sludge, and, potentially, a buffer tank at the same time.



Biological Treatment

Ecodisk® provides biological treatment of effluent without addition of chemicals. On bio-disks, set in rotation, bacteria naturally grow and form a biological turf. When exposed, these bacteria are saturated in oxygen and, when immersed, they are fed with dissolved organic matter.

The excess turf comes off and is sent to a secondary clarification stage.


Secondary Clarification

This clarification stage can be carried out by:


  • The EcodiskTM Filter, a drum filter, combined with biodisks, which provides liquid/solid separation. The sludge is evacuated as rotation progresses by a backwash system with clarified water to sludge treatment (settler digester, reed beds Biophyte, centrifuge…
  • A lamella settler combined with biodiscs. Settled sludge at the tank base is then pumped back to sludge treatment.
  • Filtration on reed beds, the EcodiskTM M, also providing sludge storage.

Features and Benefits

Easy Operation
With their open structure, bio-disks do not risk clogging. They treat wastewater without adjustment, excess bacteria naturally coming away from the disks.

Adaptation to load variations
The benefit of the bio-disks comes from the fixed biomass and the self-regulated "piston" type operation. In case of low load, only the first disks are covered and when the load increases the bacterial culture progressively colonizes all the disks.


Treatment level
The Ecodisk® treatment lines treat carbon and nitrogen pollution.

The degree of pollution treatment is modulated depending on the specific load (Cs) applied to the discs expressed in g BOD5/m²/d removal.

For carbon removal at a temperature of 12°C, the Cs is about 8 g DBO5/m²/d. Nitrogen treatment requires a Cs about 4 g BOD5/m²/d. For denitrification, effluent recirculation to the anoxic zone will be needed.

It is also possible to remove phosphorus by physical-chemical means by injecting ferric chloride in the last bio-disk stage.

Optimization of operating costs
Ecodisk® lines are not energy intensive due to EcodiskTM low power consumption drives (from 0.37 to 1.5 kW).

Compared to other treatment lines, Ecodisk® solutions are easy to operate because there is no sludge concentration or O₂ regulation, and there is no effluent recirculation required unless denitrification is planned.

Reduction of sludge quantity
This sludge is:


  • Stored in the headworks for several months, if this structure is integrated into the treatment process line. Sludge undergoes anaerobic digestion there with reduction of its volume, and increase of its dryness (up to 60 g/l), facilitating its agricultural reuse.
  • Mineralized on reed beds
  • Mechanically dewatered (centrifuge...)

Fast and low cost installation
The bio-discs are assembled in their tank in the factory and installed on a concrete slab in a few hours, using a crane.

Ecodisk® solutions' footprint is small. The bio-disks are the best option when your project requires a limited installation.

Very good landscaping integration
Without odor or noise, EcodiskTM solutions could be completely buried in order to be perfectly integrated into the environment.


Ecodisk® range Brochure (7.07 MB)


Ultra-compact solution to eliminate phosphorus and refine treatment
Aerobic Wastewater Treatment

Ecodisk® Filter

The Ecodisk® Filter process complies with even stricter effluent quality standards, thanks to its secondary mechanical filtration treatment
Aerobic Wastewater Treatment

Ecodisk® Denit

The latest generation, Ecodisk® Denit is an answer to the highest quality effluent demand in total nitrogen.
Aerobic Wastewater Treatment