Water Efficient Toilet

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Aim of the project:
The modern age of industrialization and modernization demands a growing need of clean water in all spheres of the society. If the amount of water used up in flushing is reduced significantly, it will lead to an overall saving in the cost of water extraction and processing as well as cost of waste water management. This project aims to implement a new, improved and water efficient toilet and estimate the economical and environmental advantages.

Proposed design: (Refer to visual illustrations 2 and 3 for design)
1. The toilet is box-shaped and there is a pit in the center, meaning the inner sides of the toilet never get dirty.
2. The size and shape of the seat remains the same. So, there is no compromise on user's comfort.
3. There are 2 strong water sprinklers set up in the pit in the center and 2 jets on the opposite side of the drain.
4. The base is slanting, which means lesser water is required to carry the waste material away.
5. When the button for long flush is pressed, the sprinklers in the center are activated for 4 seconds during which they complete one rotation. Then, the water jets are activated for 3 seconds during which they push all the slurry through the drain.
6. In case of the short flush, only the procedure by the sprinklers is carried out.
7. When the button for disinfecting the toilet is pressed, the process for long flush is repeated with a mixture of water and disinfectant.
8. Like the current system, the slurry after flushing is carried through a network of pipes to the place of treatment.
9. There is a provision for placing things like mobile phone, newspaper, tissue paper, room freshener etc. on the toilet seat itself.

Water consumption details:
1. Typical water outflow per use for a sprinkler: (4 seconds)*(3 outlets)*(12 m/s)*(3 mm2) = 0.45 liters
2. Typical water outflow per use for a jet: (3 seconds)*(1 outlet)*(4 m/s)*(100 mm2) = 1.2 liters
3. Water usage for a long flush = (2*0.45)+(2*1.2) = 3.3 liters
4. Water usage for a short flush = (2*1.2) = 2.4 liters
5. The process uses electricity but the cost and amount is negligible.

The Impact: (With reference to water usage of France)
1. With the new design, water consumption per capita per day by toilets will drop down from 35 liters to a maximum of 20 liters.
2. This means we save more than 40% of the water used in flushes and more than 5% of domestic water.
3. We save (66 million)*(15 liters)*(365 days) = 0.36 billion m3 of water annually when only France is considered.
4. Economically, this amounts to a saving of (66 million)*(5/100)* (360 EUR) = 1.19 billion EUR of billing annually for the French people
5. Considering the cost of toilets available today, the cost of this design can be estimated at 90 EUR. This translates to a payback period of 5 years.


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  • Name:
    Hrishikesh Kulkarni
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  • Hrishikesh's hobbies and activities:
    Automation. Basketball. Travel.
  • Hrishikesh is inspired by:
    With the conventional sources of energy depleting fast, questions being raised about the future of this planet, and use of non-conventional sources not so common yet, I think this is the best time to innovate. I think our generation is lucky enough to be living in this time period of human evolution and there are so many opportunities of inventing for better living. The simplest of ideas, being applied rightly, can make a huge impact.
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