NCWR

About NCWR

Do you know about grey water?

In a nutshell

In this activity we find out what is “greywater”, how it is produced and reused!

45 min

12-13 years old

In class

Our objectives

In this activity you will:

  • Find out that greywater is a non conventional water resource.
  • Discuss which are the uses of the recycled grey water .
  • Learn how grey water gets cleansed.

Play & Learn

Can we reuse the soapy waters after washing of our hands?

Water-readings

What is grey water?

Greywater is the household’s wastewater other than that coming from toilets (), meaning the wastewater from the washbasins, the shower, the laundry, etc. This wastewater can be relatively easily, cleaned and reused.

Today the technology offers a lot of different options for an effective greywater treatment. The most common greywater systems refer to the treatment of the water from the shower, bathtub, washbasin and the washing machines (laundry). The greywater from the kitchen sinks and the dishwashers require more complex and costly technologies.

Play & Learn

Check which activities produce greywater:

Actually, many car washing stations today are equipped with the system for collecting, filtering/cleaning and reusing the water used.

Water from the swimming pool is not considered as greywater because it contains a lot of chlorine that can be toxic.

Water after taking a shower it mainly contains remains of soap, shampoo, shower gels, etc that can be relatively easily removed through filters

This is “black water” and it goes to the sewage system (and through that to the wastewater treatment plant).

These waters contain big amounts of grease and oils and is more complex to be recycled.

Water from the washing machine contains remains of detergents that can be easily removed through filters

These waters are containing big amounts of grease and oils and it is more complex to be recycled.

It contains some debris and remains of soap and can be easily get cleaned.

Water-readings

How do we treat greywater?

Greywater treatment is realised through an automatic closed system that includes pipes, pumps, filters and tanks. Firstly, greywater from the washbasins and the shower/bathtub is collected through pipes and led to filters that hold the large suspended solids.

Then, water is led to the treatment tanks where it is aerated, re-filtered,  and to kill any  microorganisms that may exist.

Finally, water is stored to a tank. With the help of a this treated greywater is transferred inside and outside the building or in the case that the storage tank gets full, is led to the sewage network.

This system is closed and operates automatically so that we do not come into contact with this water for our safety (hygiene reasons). We control the system through a control unit and we need to maintain it following the manufacturer’s provisions.

Where can we use the treated greywater?

Greywater, once treated, can be consumed for uses that do not require crystal clear water (secondary uses); this is means that is not allowed to be used for personal hygiene (bathing, showering) cooking or drinking! It is mainly used in the toilet flushing and for watering the green spaces. Actually we can water with it trees plantation and flowers but not the edible leafy vegetables. In fact, watering should be done automatically at the root of the plant, avoiding sprinklers and open watering channels.  A household that recycles its greywater can save up to 1/3 of water coming from the water supply network!

Stop and wonder

In your groups, discuss about the following:


  1. Why don’t we all have greywater systems in our houses since we achieve great water saving with it?
  2. Why we avoid watering the vegetables with treated greywater?
  3. Why we opt for automatic watering system when using treated greywater and avoid hoses and open watering channels?

 

 

Play & learn

Drag and drop the parts of a greywater system in a building to the right places.

 grey-water-system quiz-hotspot
1
2
3
4
5
6
7
8
9
10
  • 1 1 filters (1)
  • 2 2 disinfection
  • 3 3 control unit
  • 4 4 storage tank
  • 5 5 aeration pump
  • 6 6 sewage network
  • 7 7 greywater sources (1)
  • 8 8 greywater sources (2)
  • 9 9 treatment tanks
  • 10 10 filters (2)

Water shares


Water meter

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Way forward

Dive in…

Rainwater harvestingWastewater treatment – Desalination unit if you want know about other non-conventional water resources.

Examples of greywater systems if you want to read more  about an installation/construction of a greywater system

Go back to the homepage!

The water basins

Water in the city

Desalination

Do you know about grey water?

Rainwater harvesting

Greywater recycling in practice

Wastewater treatment

The water cycle in a bowl!

Waterworks through time

Climate change challenges

Rainwater Harvesting Systems in practice

Reduce-Reuse-Recycle

Water resources

Where do I begin?

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In this activity we learn what a water drainage basin is and why it is important for the experts to study it.

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Desalination

Let's find out how sea and brakish water can become a freshwater resource!

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Let's find out what "greywater” is and how we can use it!

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Greywater recycling in practice

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Wastewater treatment

In this activity we are informed about how wastewater is treated and what we can do with the treated wastewater.

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