Design of poster :D

Here's a droplet of water!

I think our poster should roughly about this shape. Yup, can add in hands and legs if u all want!






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Mind me complain a bit...I seriously hate the internet here. I can't upload picture here. D:

Microfiltration

Microfiltration is a filtration process which removes contaminants from a fluid (liquid & gas) by passage through a microporous membrane. A typical microfiltration membrane pore size range is 0.1 to 10 micrometers (µm). This process requires feed rates of very high velocities at low pressures. Each microfiltration module requires a 30 GPM cross flow with a feed pressure from 30 to 40 PSI. (GPM is gallons per minute, a unit for flow rate while PSI is the unit for pressure in United States, EES unit. 1PSI=1 lb/in2)Microfiltration is not fundamentally different from reverse osmosis, ultrafiltration or Nanofiltration, except in terms of the size of the molecules it retains.
In microfiltration, low pressure membranes were selected to remove turbidity spikes and pathogens without chemical conditioning. As low pressure membranes get more and more accepted by people, this technology begins to used to apply on waters with more solids and higher levels of dissolved organics. Some of these waters required chemical pretreatment, including pre-chlorination. These shifts in water quality triggered change in low pressure membrane technology. Improvised processes were introduced to deal with higher solids and chemical compatibility.


Basic Principles
Membranes are semi-permeable thin barrier sheets. Synthetic membranes are used to remove different solutions and particles in the water treatment process.
There are five types of membrane processes (see table below).





Different Pressure Processes

Reverse osmosis and microfiltration as well as ultrafiltration are often described as being pressure processes. Actually, they are very different from each other :
• Mircofiltration is a direct continuation of conventional filtration that makes it possible to remove particles smaller than a micron such as colloids and bacteria.
• Ultrafiltration are even better in removing particles. With this process, viruses and heavy molecular organic compounds can be removed.
These two processes use a straining technique and therefore separation depends on the size of the pores and which species are chosen.
How Microfiltration Works

When the untreated water is pumped into the filters and forced through the holes in the sides of the straws, the particulate matter will accumulate on the outer wall of the straws. Then, the filtered water flows through the straws and out of the array, then into the dstribution and storage system. During this process, chemicals are added for various purposes. Flouride is added for healthy teeth; polyphosphate for homeowners with lead piping and a small amount of chloride to continually disinfect the distribution system.

Through microfiltration, we can eliminate the use of chemicals in the treatment process and decreases the use of chlorine for disinfection up to 50%.

Purity of NEWater

By comparing with different types of water, we will get a conclusion on how pure is the water from NEWater.

Distilled water

During the process of distillation, the water is boiled, followed by collecting of steam. After that, it is condensed. Through this process, many harmful bacteria and substances will be removed. However, the natural minerals in the water will not be there anymore.

Mineral water

On the other hand, mineral water contains dissolved minerals that are either naturally or artificially prepared. This water has been filtered, so there will no be any harmful substances in the water.


NEWater

In the NEWater process, water has already gone through microfiltration and reverse osmosis before the process of UV disinfection. The UV light will be absorbed by the bacteria and viruses, rearranging the genetic material. Thus, the bacteria and viruses can no longer reproduce, can be considered as dead.

In reverse osmosis, bacteria and viruses with smaller particles than water particles will still be able to pass through. Moreover, the mineral will also be removed from water. However, wit UV distillation, even those small viruses can be removed.



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This should be the last part on introduction of NEWater. I will put up my part later :D

Introduction of NEWater

NEWater is reclaimed water which has gone through treatment in NEWater Pants that consists of four processes: Microfiltration, Reverse Osmosis, water Conditioning and Ultraviolet Disinfection. After these four processes, the pure water can be used for both protable and non-portable purposes.

The below are the basic steps for the four processes with brief explanation. We will be researching more on the individual process to find out more about the Physics principle behind it.
In the first step of NEWater, water will go through microfiltration. It consists of tiny fibers which traps the solid (mostly bacteria and harmful micro-organisms) in the tubes. Besides, it can ensure a good stream of steady flowing water to prevent blockage and clogging up.

Later in the process of reverse osmosis, water will be applied pressure that would allow the water to flow from the concentrated side to the less concentrated side through a partially permeable membrane. In this process, viruses and dirty content like nitrate, chloride, sulphate etc will be removed.

For safety precaution, a back up process Ultraviolet rays is added in to wipe out harmful particles in one zap.

Lastly, the cleansed water is mixed with reservoir water to give it a “water taste” and is ready to be drunk.

History of NEWater

There are many reasons of why NEWater is invented. One of the reason is that Singapore’s daily water consumption keeps increasing daily. As the population in Singapore and the growth of economy, more water is needed to maintain our daily life. Besides, as water is easily accessible, more and more people are taking it for granted. They waste water and use water uncontrollably, without putting any thought to it.

Singapore has been buying water from Malaysia since 1920. Currently, there are two agreements between Singapore and Malaysia that will end in 2011 and 2061. As 2011 draws near, Malaysia and Singapore are still not able to agree on terms for another water treaty. If this continues, Singapore will be in a situation of shortage of water. Hence, other sources of water needed to be created and the government has come up with the idea of NEWater to serve the purpose of being the fourth national tap to fulfill the growing water consumption.

It seems like I've forgotten to post the most basic part: the part about the NEWater. So I will post them up now :D

Second meeting today (;

Hello all,

Today will be the review of the meeting we had this morning about the physics poster which we are to hand in on Friday. The meeting was about 20 minutes and we came up with another job allocation to do our project, so please take note if any of you had missed out anything during the meeting! :)

We discussed the things we want to put in the poster:

1) The process of making Newater which involves physics, mainly the four processes we have researched before - Ultraviolet Disinfection, reverse osmosis, water conditioning and microfiltration.

2) Advantages and disadvantages of Newater

3) Pictures

4) Interesting facts about Newater

5) Singapore's reliance on Newater and how it is going to affect us in future

Regarding the job allocation, it goes like this, because of different CCA timing and time constraint okay:

Sijia + Amanda will do on Wednesday after school in class. We will probably do half of the poster first, then on Thursday after school, Huiyan + Zheng Liang will finish the poster. Hopefully, everything can be done by then and we do not need to rush on Friday :D

We can do it everybody!

Reverse Osmosis

REVERSE OSMOSIS :D

Reverse osmosis is utilize in the second stage of the NEWater production process and it is also the thrid barrier after the conventional wastewater treatment process and microfiltration or ultra filtration.

Osmosis is the movement of water from a region of HIGH concentration to a region of LOW concentration through a PARTIALLY PERMEABLE MEMBRANE. From the word REVERSE osmosis, it suggests that this process is the opposite of osmosis. Osmotic pressure is the basis of reverse osmosis. In reverse osmosis, water particles move from a region of LOW water potential to a region of HIGH water potential through a PARTIALLY PERMEABLE MEMBRANE. In this process, the membrane filters out undesirable materials such as bacteria, viruses, heavy metal, nitrate, chloride, sulphate, disinfection by-products, aromatic hydrocarbons and pesticides as these materals are to large to pass through the membrane and only water particles are able to pass through it.