Basics of domestic water recycling

JA Carney wrote in her 1845 poem, little drops of water and tiny grains of sand make up the mighty ocean. One of the most effective ways of doing this in everyday life is greywater recycling, a method of recycling wastewater from kitchen sinks, showers and laundry fixtures.

Types of waste water:

1. Black water - This water originates from toilet fixtures, dishwashers, and food preparation sinks. It is made up of all the things that you can imagine going down the toilets, bath and sink drains. They include poop, urine, toilet paper and wipes; body cleaning liquids, anal cleansing water and so on. They are known to be highly contaminated with dissolved chemicals, particulate matter and is very pathogenic. This water is not fit for recycled use.
2. Grey water - This water originates from non-toilet and food fixtures such as bathroom sinks, laundry machines, spas, bathtubs and so on. Technically it is sewage that does not contain poop or urine. Grey water is treated very differently from Black water and is usually suitable for re-use. more appropriate term for this water would be "Used Water".
3. Yellow water - This is basically urine collected with specific channels and not contaminated with either blackwater or grey water.

We are going to focus only on Grey Water in this post.


Points to be noted:

1. System DESIGN and OPERATION must consider 
2. Public health risks (grey water can contain micro-organisms and may transfer diseases and present health risk) 
1. Spray irrigation and direct contact with vegetables and plants is forbidden 
2. Avoid human beings direct contact
3. Water & nutrient balance and chemicals properties 
4. Prevention of pollution of soil, groundwater, surface water , marine environment (use detergent that are friendly to environment and should not discharge into storm drainage system) 
5. Reuse purpose - to be suitable to the degree of treatment and method employed for reuse
6. separate greywater from blackwater system
7. provide suitable treatment unit
8. reuse (mainly by irrigation) 
1. Subsurface - if not treated and/or not disinfected 
2. Above surface - if treated and disinfected

Uses of recycled Grey water:

With proper treatment grey water can be put to good use. These uses include water for laundry and toilet flushing, and also irrigation of plants. Treated grey water can be used to irrigate both food and non food producing plants. The nutrients in the grey water (such as phosphorus and nitrogen) provide an excellent food source for these plants.

Benefits of Grey water:

• Reducing the need for fresh water. Saving on fresh water use can significantly reduce household water bills, but also has a broader community benefit in reducing demands on public water supply.
• Reducing the amount of wastewater entering sewers or on-site treatment systems. Again, this can benefit the individual household, but also the broader community.

Sources:

eschooltoday

The Better India


P.S.: personally i am looking to install grey water recycling plant in my home. So i will learn more about this process and will keep posting updates on this topic. Stay tuned.