NEWater

Hi everyone,

Today I will telling you all about NEWater.


So what is NEWater?


NEWater is the name of the recycled wastewater produced by Singapore's Public Utilities Board. It is potable and fit to be consumed by humans. It is mostly used in industries that needs large amount of high purity water. In order to save water, NEWater is thus used.


So how did NEWater came about?


In 1974, water recycling started. However, due to cost and reliability issues, the experimental plant closed down in 1975. Water recycling was not used until 1998. In 1998, Singapore's Public Utilities Board (PUB) and the Ministry of the Environment and Water Resources (MEWR) initiated the idea of NEWater. This time, they started the idea of water recycling again as they did not want to rely too much on Malaysia for water. The idea was successful! Water was then used. In 2001, they then tried to increase water supplies for non-potable use so that the demand for water in reservoirs will be lower.


Where is the production of NEWater done?

Singapore had 5 NEWater factories, at Bedok, Kranji, Ulu Pandan, Seletar, and Changi. There is also a visitor centre near Tanah Merah MRT station. That is used for educational purposes and also for production.

What are the steps in the production of NEWater?


1. The used water will be conventionally treated in the Water Reclaimation Plants

2. The water will then be filtered by using ultrafiltration. Suspended solids, colloidal particles, disease-causing bacteria, some viruses and protozoan cysts will be filtered out. The water will then only contain dissolved salts and organic molecules.

3. The filtered water will then go through the process of Reverse Osmosis (RO).

4. UV disinfection then introduced to ensure the water is clean and all organisms are inactivated. This will act as a safety precaution.

5. Alkaline chemicals will be put to restore the pH balance of the water and NEWater is then safe to be consumed by humans.

Where is NEWater being used?

The 3 factories produced about 75700m³/day and 6% of this is used for indirect potable use. ( contributes 1% to Singapore’s potable water requirements (13m³/s)) while the rest used at water fabrication plants and other non-potable applications in industries.

This is a NICE video on NEWater!!! http://www.youtube.com/watch?v=K1rb13g6dTU

Reverse Osmosis

Reverse osmosis is the action of "cleaning" water. Or in other words purifying water. Reverse Osmosis is done by filtering solutions through a partially permeable membrane in high pressure. That will remove many types of large molecules and ions from the solution. So why is reverse osmosis important?

In the world now, among the 100% of the water in the world, only 3% is drinkable, the other 97% of water are unsuitable for us to use. And among this 3%, about 69% of water are locked up in glaciers and icebergs in the North and South Poles. Thus, the amount of drinkable water that can be easily obtained are low. And to overcome this problems, reverse osmosis are used. This is to allow those people living in drought-stricken areas to have enough water.

So how is reverse osmosis done?

Reverse osmosis are done by:
Step 1: Sea water will pass through the partially permeable membrane using pressures higher than the osmotic pressure. Only water and some bacteria will be able to pass through the membrane as big molecules like the salt molecules are too big to pass through the membrane.
Step 2: The water is now cleaned by sanitizing it with chemicals. The chemicals are suitable for humans. The water will now be clean. However, for safety precautions, the water will be checked for anymore bacteria. If the water is bacteria-free, the water will be used.

Is reverse osmosised water used in other areas other than for drinking?

Yes. Reverse osmosised water are also used in:

• Food industries that needs large amounts of water
• Car Washing
• Maple Syrup Production
• Hydrogen Production ( water is H2o which means it contains 2 molecules of hydrogen and 1 molecule of oxygen. )
• Reef Aquariums

Now lets enjoy a nice video of reverse osmosis

http://www.youtube.com/watch?v=5MDPBWKdSag

Reflection of Term 3 Science Lesson

Hi everyone,

I will be telling you all about my reflection of term 3 science lessons. In term 3, we were taught Systems to organs to tissue to cell. Let me tell you about that. Many cells will form a tissue ( IT IS NOT TISSUE PAPER ). Many tissues will form an organ. Many organs will form a system. Many system forms a body. From this, we can see that 1 tiny cell can help us by much! One example of this link is: Muscle Cell --> Muscle Tissue --> Muscle --> Muscular System.

Next, we were taught Energy and Forces. From that lesson, we can see that forces can help us in many ways, and also cause destruction. One example that our science teacher told us about forces is an example of a fat person wearing a pair of high heels shoes and another person who is lighter in mass and wears a pair of high heels shoes. Both people steps on a sponge. The result is that the heavier person will give out a greater force than that of the lighter person.

All in all, the lesson conducted in Term 3 were fun and exciting. I will wish if we can have much more of these lessons.

Thanks,
Aloysius Chan