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

Reflection of Term 2 Science Lesson

Hi all,

Today I will be talking about my reflection on Term 2 Science Lessons.

In term 2, I learnt about Diversity and Interactions, like solvent and solutes, seperation techqinues, elements and many other things. I feel that the lessons on these topics were fun, as most of the lessons were conducted in the science lab and we can get to do many experiments. This thus, made the lessons fun. However, I think that the lessons will be more fun if there is longer time for us to do the experiments as I feel that experiments are better than having only the notes and not much experiments. This is because experiments are 3D and it will allow us to do it ourself and in other words, meant that we can have our own experience on doing the experiment.

Thanks,
Aloysius Chan (03)

Reflection of Term 1 Science Lesson

Hi all,

Today I will be telling you my reflection of term 1 science lesson.

That is my first term having science lesson in secondary school. After the long December break, I have lost most of my Primary School Science memory. Thus, during the science lesson in HCI, it was a tough time for me. However, I still, like during the science lessons in my Primary School, love it and it is a fun time for me. The science lessons were innovative and not boring which made our class get captivated and engrossed in the lessons. The first lesson was on bunsen burner and we had lessons in the science lab. It is a fun and exciting time for me as that is my first time being in a science lab ( my primary did not have a science lab , or it did and my teacher did not bring us there ).

Thanks,

Aloysius Chan

Why are we lighter at the equator than at the poles??

Hi everyone, today I am going to talk about this question: Why are we lighter at the equator than at the poles?

Before I go into this topic, for the benefit of people who does not know the difference between weight and mass, I am going to talk about them. Mass and weight meant the same in daily life, but, in science they are different. Weight means how strong gravity pulls on that matter while mass means the amount of matter that item have. Also weight is measured in Newtons (N) while mass in measured in kilograms (kg), grams (g) etc. An example is that: Person A have a mass of 50 kilograms and weighs 491 newtons on the surface of the Earth; on the surface of the Moon, Person A still has a mass of 50 kilograms but weighs only 81.5 newtons. This is the difference of weight and mass.

Now I am going my topic. We will be lighter at the equator is because of the gravitational acceleration. The cause of the difference of gravitational acceleration is due to the planet's rotation around its axis. The gravitational acceleration is less at the equator than at the poles. At the equator, the true gravitational acceleration is 9.8144 m/s² . At the poles, the gravitational acceleration is 9.8322 m/s². The difference of 0.0178 m/s² between the gravitational acceleration at the poles and the true gravitational acceleration at the equator is because objects located on the equator are about 21 kilometers further away from the center of mass of the Earth than at the poles, which corresponds to a smaller gravitational acceleration. Thus we will weigh less at the equator than at the poles.

Another factor is that the earth is non-spherical and thus the shape of the earth will be like a little "squashed". This thus will affect the amount of gravitational force on the poles and at the equator as the further the place is from the center of gravity, the lesser the amount of gravity pulling the items on the place down.

In summary, there are two contributions to the fact that the effective gravitational acceleration is less strong at the equator than at the poles. About 70 percent of the difference is contributed by the fact that there is a difference in the gravitational acceleration, and about 30 percent is due to the non-spherical shape of the Earth.

I have come to the end of this topic. Thank you and good bye!

Aloysius Chan

Websites I went to get the infomation: http://en.wikipedia.org/wiki/Equatorial_bulge

http://www.google.com.sg/search?sourceid=chrome&ie=UTF-8&q=gravity+difference+on+poles+and+equator

Germs help sushi digestion

This picture shows the photo of the germ, Zobellia galactanivorans.

Hi everyone who reads this post, this report is taken from The Straits Times Online. The URL of this webpage is: http://www.straitstimes.com/BreakingNews/TechandScience/Story/STIStory_512027.html and you can read the real report there. Below is my reflections on this report.

Actually this report is about Japanese being able to digest sushi and other seaweed-wrapped delicacies easily, which was found out by scientists. After reading this article, I feel that this is a great discovery as scientists might be able to use this discovery to probably inject these bacteria into human bodies and maybe this would help those people who had digestive problem and could not eat these delicacies.

But I wondered if is there any side effects that will cause other problems (eg. heart problems etc.). But if there is no side effects, I really support the scientists to inject the bacteria into people bodies as this will help a lot people, like my mother. My mother had digestive problems and could not eat these foods. Once she ate these foods, she would have bloated tummy and feel like vomiting. In my opinion, this is because in her stomach, there is a lack of these bacteria and the stomach could not digest the food well thus, causing these effects.

This is the websites I went to get my infomation: http://www.straitstimes.com/BreakingNews/TechandScience/Story/STIStory_512027.html

Thanks,

Aloysius Chan