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NEWater Separation Techniques Science ACE

NEWater Separation Techniques Science ACE. By Eric Seow (8) Class: 1P1. Separation Techniques: Background. There are many separation techniques including Filtration, eg to separate tea leaves from tea Magnetic attraction, eg to recycle metal. Water reclamation techniques.

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NEWater Separation Techniques Science ACE

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  1. NEWater Separation TechniquesScience ACE By Eric Seow(8) Class: 1P1

  2. Separation Techniques: Background There are many separation techniques including • Filtration, eg to separate tea leaves from tea • Magnetic attraction, eg to recycle metal

  3. Water reclamation techniques • Reusing treated water is not new. In countries with long riverine systems, upstream communities use the water and discharge the used water after treatment back into the river. Successive downstream communities then reuse the water several times, before the river finally flows into the sea. • New technology is making it cheaper to recycle water on a large scale. Superior filters and membranes are significantly reducing the cost of microfiltration and reverse osmosis.

  4. Water reclamation overseas • Water reclamation is a growing trend worldwide. Florida and California were the first to approve the use of reclaimed water for in-building piping and use in flushing toilets. • As Australia continues to battle drought, reclaimed effluent is becoming a popular option.

  5. Water reclamation in Singapore • Singapore has been introducing new ways to increase water supply since 2001. • The use of NEWater for wafer fabrication processes, non-potable applications in manufacturing processes as well as air-con cooling towers in commercial buildings would free large amount of potable water for other potable purposes. • Singapore has gone one step further: using NEWaterfor indirect potable use in Sep 2002. This means mixing and blending NEWater with raw water in the reservoirs before undergoing conventional treatment at the waterworks for supply to the public for potable use. The amount will be increased progressively to about 2.5% of total daily water consumption by 2011.

  6. NEWater introduction • What is NEWater? It is treatedwastewater (sewage) that has been purified using dual-membrane (via microfiltration andreverse osmosis) and ultraviolet technologies, in addition to conventional water treatment processes. • The water is potable and is consumed by humans, but is mostly used for industry requiring high purity water.

  7. NEWater status today • Singapore has five operational NEWaterfactories -- Bedok, Kranji, UluPandan, Seletar and Sembawang. • There is a Visitor Centre near Tanah Merah MRT Station, which contains a working NEWater factory for educational purposes.

  8. NEWater separation technique • Step 1: The first barrier is the conventional wastewater treatment process whereby the used water is treated to suitable standards in the water reclamation plants. • Step 2: The second barrier is the NEWater production process known as Microfiltration (MF). In this process, the treated water passes through membranes and filters out suspended solids, colloidal particles, and other viruses and bacteria. Filtered water enters the membrane.

  9. NEWater separation technique • Step 3: The third barrier of the NEWater production process is known as Reverse Osmosis (RO). In RO, a semi-permeable membrane  is used to allow only tiny molecules like water molecules to pass through, barring undesirable contaminants such as bacteria, viruses, etc. • Hence, NEWater is RO water and is free from viruses and bacteria and contains very low levels of salts and organic matters.

  10. NEWater separation technique • Step 4: At this stage, the water is already of a high grade water quality. The fourth barrier of the NEWater production process really acts as a further safety back-up to the RO. In this stage, ultraviolet disinfection is used to ensure that all organisms are inactivated. • Some alkaline chemicals are added to restore the acid-alkali or pH balance, the NEWater is now ready to be piped off.

  11. NEWater separation technique • In fact, RO is now used commonly in many other areas. This includes the production of bottled drinking water and production of clean water for the wafer fabrication and electronics industry. • RO is also used to recycle used water to drinking water on space shuttles and on International Space Stations.

  12. How safe is NEWater for drinking? • The quality of NEWater consistently exceeds the requirements set by international bodies such as WHO and is, in fact, cleaner than the other sources of Singapore's water. • Plans are under way to increase the amount of NEWater in indirect potable use up to 3.5% by 2011.

  13. The End

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