Science ACE

How isNEWaterObtained? By Royce Chan (1O104) Singapore’s independent source of water. Powerpoint Templates

How isNEWaterobtained?,[object Object]

The History of NEWater Water recycling in Singapore began in 1974 but the experimental treatment plant was closed a year later due to cost and reliability issues. The Singapore Water Reclamation Study (NEWater Study) was initiated in 1998 by the Public Utilities Board (PUB) and the Ministry of the Environment and Water Resources (MEWR). The aim of this study was to determine if NEWater was a viable source of raw water for Singapore's needs.

The History of NEWater (Cont.) NEWater and desalination were explored as means to reduce reliance on water imported from Malaysia, which has been a source of friction over the years. Also, while the Malaysian government is bound by two treaties to sell Singapore water until 2011 and 2061, it is under no obligation to do so after these dates. In 2001, PUB began an effort to increase water supplies for non-potable use. Using NEWater for these applications would reduce the demand on the reservoirs for potable water.

Why is it needed? Singapore is a very small island country situated at Southeast Asia. Our country is so small that we do not have any natural resources. Thus, we are very dependant on import of basic necessities like fuel and water. Our main source of fresh water supply comes from our good neighbour, Malaysia.

However, with the increasing population and the increasing demand for water, the government had to think of ways other than buying water from Malaysia. A desalination plant would be very costly and also a lot of resources are required to build such a facility. Our water bills would increase if that happens.

Luckily for us, the Public Utilities Board (PUB) and the Ministry of Environment and Water Resources (MEWR) started a joint initiative in 1998, known as the Singapore Water Reclamation Study. After a few years of intensive laboratory experiments and rigorous testing, NEWater was born and has been supplying our reservoirs and taps since February 2003.

How isNEWaterobtained? As mentioned earlier, NEWater is waste water. This waste water goes through a series of filtration known as reverse osmosis to sieve out the impurities before going into our reservoirs and taps.

Why use this method instead of desalination? The answer to this question is very straightforward: Desalination is EXPENSIVE

With this method, water is recycled, helping us to cope with our rate of water consumption. The process is much faster and easier than desalination, and also considerably cheaper!

Stage 1- Micro Filtration The waste water is first treated at the UIV Pandan Sewage Treatment Works to globally recognized standards. Water here is removed of most harmful chemicals and is known as non-potable water. This water can be used in industries for machine and equipment cleaning. This water is then transported to the NEWater plant to go through the first stage of filtration.

Micro Filtration The first stage of NEWater production process is micro filtration. The used water will pass through membranes to filter out small water molecules will pass through the pores of the membranes and suspended , colloidal particles, disease-causing bacteria, some virus and protozoan cysts. These would not be able to go though the pores. The filtered water that goes through the membrane contains only dissolved salts and organic molecules.

Stage 2- Reverse Osmosis The second stage of the NEWater production is known as Reverse Osmosis0 In Reverse Osmosis, a semi-permeable membrane is used. The membrane used has very small pores which only allow water molecules to pass through. Undesirable contaminants such as bacteria, viruses, heave metals, nitrate, chloride, sulfate, disinfection by-products, aromatic hydrocarbons and pesticides cannot pass through the membrane After this process, the water is already bacteria-free and also contains very low levels of salts and organic matters.

Additional step- Ultra Violet Radiation After the second stage of the NEWater production, the water is already of a high grade quality. At the third stage of the production, ultraviolet or a propagating wave in space with electric and magnetic components is used to ensure that all organisms are inactive. In other words, whatever was alive in the water should be dead by now.

After this stage, the purity of the product guaranteed. The ultraviolet disinfection is actually a safety back up to Reverse Osmosis. With the addition of some alkaline chemicals to restore the P.H. (measurement of acid) balance, NEWater is now ready to be piped off to our reservoirs and taps.

Additional Information You must be wondering, is NEWater the only source of water available in Singapore? The answer is NO. Some of the water is actually purchased from our neighbouring country, Malaysia. Some are from desalination plants in Singapore.

Here is where our water comes from

What is Desalination? Desalination refers to the processes of removing salt and several minerals from seawater. Water is desalinated in order to convert salt water to fresh water so it is suitable for human consumption or irrigation. Sometimes the process produces table salt as a by-product. Desalination is used on many seagoing ships and submarines. Most of the modern interest in desalination is focused on developing cost-effective ways of providing fresh water for human use in regions where the availability of fresh water is, or is becoming, limited.

Large-scale desalination typically uses extremely large amounts of energy as well as specialized, expensive infrastructure, making it very costly compared to NEWater. In some countries, nuclear-energy (heat) is used to speed up the process of desalination. Instead of evaporating the water to dryness, it is boiled until it dries up. This is very efficient but it is not eco-friendly and nuclear radiation is very dangerous, if there happens to be a leak.

Science ACE

Recomendados

Recomendados

Mais conteúdo relacionado

Mais procurados

Mais procurados (20)

Semelhante a Science ACE

Semelhante a Science ACE (20)

Último

Último (20)

Science ACE