Greywater Recycling


Greywater Recycling plant treatment for water reuse

Category / type: Water recycling plant, non-potable use.
Application: toilet flushing, garden watering, car wash, laundry,domestic, commercial, public.
Flow rate: from 500 up to 10.00 litres per day (packaged and/or site assembled) and more than 50 tailor-made.
Normative references and guarantees: DIN 4046:1983-09 water-supply, terms.
Technology: membrane, ultrafiltration, biological.
Target: drinking water resource protection, dual water networks.

Greywater (or graywater) is any non-industrial wastewater generated from sinks, dishwashers, showers, baths and washing machines. It doesn’t include toilet wastewater, classed as blackwater.
Greywater is easier to treat and recycle than blackwater, due to its lower levels of contaminants and patogens.
Recycled water can replace fresh water (drinkable) in many instances, saving money decreasing supply cost and increasing the effective water supply in any regions.
A gray-water treatment plant collects and treats greywater to guarantees a sufficient quality for specific reuse purposes.


How It Works

Greywater is a valuable resource that should be efficiently used due to it’s full potential. It may contain traces of dirt, food, grease, hair, and household cleaning products.
Greywater recycling plants can treat and let reuse large volumes of water, and play a reliable role in water conservation in dense urban housing developments, food processing and manufacturing facilities, schools, universities, and public buildings.
Since greywater contains fewer contaminants than black water, it is generally quite easy to recycle, usually after a physical treatment, such as a basic filtration process, able to remove large solid particles, and further treatments as fine mash filter or ultrafiltration (UF), osmosis, etc. Biological treatments, as those applied in sewage plant, can also be used, helping in preventing bacterial growth and odour problems.
Because water may contain pathogens, a final disinfection stage is always needed (UV ray, chlorine, ozone).
Greywater treatment plants are available in different sizes due to different consumption needs.
In order to recycle water, it is necessary to have two separate hydraulic circuits that supply waters into buildings. So for all new buildings, but also for restored ones, it’s strongly recommended to take into account a dual water networks during construction phases.


Operation and maintenance

Minimize contact with greywater because it could potentially contain pathogens. The system should be designed for dual water networks where the not drinkable water pipe must be carefully signed.
System can be designed to conform to a variety of system configurations and uses. Different sized grey water processors and additional grey water storage tanks can be added to adapt to variety of applications.
Note that not all types of greywater can be recycled with the same plant, since not all greywaters are equal in pollutants charateristic.
The regular maintenance is absolutely necessary for the proper functioning of the system. See manual of use and maintenance of produtct.
Recovered greywater are absolutely not potable. It is suggested do not use it on edible parts before the fruit and vegetables before harvesting. Greywater is not permitted to run off so it is not allowed to use sprinklers. Ensure all pipes are marked to indicate greywater. The use and the choose of less-aggressive detergents allow to use treated water on more plants.


Regulatory framework

According to DIN 4046 Water-supply; terms; DVGW code of practice (Wasserversorgung; Begriffe; Technische Regel des DVGW), process water is defined as water with different quality characteristics serving commercial, industrial, agricultural or similar purposes. In connection with greywater recycling, it also includes water which is used in households and trade and which does not have to be of a drinking water quality, such as water used for toilet flushing, irrigation, for cleaning purposes or for laundry.
There are local regulations and incentives for the realization of systems for recovering water.


Features and benefits

Greywater can replace fresh water in many instances, saving money and increasing the effective water supply in any regions.
Greywater recycling in apartment blocks, hotels, schools, townhouses and commercial buildings, is rapidly becoming mainstream.
Treated greywater can be reused for indoor-toilet flushing as well as outdoor garden irrigation and, in some cases, for laundry and washing machine.
This kind of systems save substantial amounts of drinking water up to 60% of conventional usage patterns.
Grey water use greatly extends the useful life and capacity of municipal treatment plants in term of wastewater flow decreasing, higher treatment effectiveness and lowering treatment costs.
Taking into account that water price is increasing, a grey water recycling system will be amortized very fast.

Advantages (benefits)

  • system simplicity;
  • potable water resource saving;
  • money saving;
  • less strain on septic tank or treatment plant;
  • plant growth;
  • reclamation of otherwise wasted nutrients.


  • dual water network;
  • pay attention to no drinking water (warning sign);
  • electric pump or pressure system needed;
  • periodic maintenance required.


Products in category Greywater Recycling

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