With that in mind, the government has built a desalination plant in Tuas in 2005 which uses the cutting edge technology "reverse osmosis" instead of desalination to obtain drinking water from seawater. This plant supplies about enough water to meet around 10% of the national demand. The production of NEWwater from wastewater also uses the process of reverse osmosis.
Refer to textbook page 25 for the process of reverse osmosis.
Thinking questions:
- Suggest possible reasons why Singapore decided to use reverse osmosis and not distillation to obtain pure water from seawater.
- What are some of the strategies that Singapore has taken to diversify Singapore's water resources?
Online Resource:
http://en.wikipedia.org/wiki/Water_resources_of_Singapore
http://en.wikipedia.org/wiki/NEWater
1. The process of distillation requires the burning of fossil fuels to heat up and evaporate the water. This process requires a lot of time and fuel. Also, since Singapore is a country that has no sources of fossil fuels, the purchase of fossil fuels to be used to distill sea water would be costly. Therefore, reverse osmosis is chosen as it over rides the the advantages of using distillation.
ReplyDelete2. Singapore imports a small portion of water from Malaysia. Rainwater is also collected from water catchment areas and storm water canals. To add on to the amount of water, used water is recycled through the process of reverse osmosis at the Newater plant.
1. Distillation utilizes a heat source in order to vaporize water. Such burning will result in high cost of purchasing fossil fuels. But the main reason is that distillation is not so efficient in removing volatile chemicals with low boiling point found in the sea water whereas reverse osmosis with the help of carbon filters, can remove chloramines best. Hence, reverse osmosis is more preferred by the government rather than distillation.
ReplyDelete2. Singapore has contracts of import of water from the neighboring country like Malaysia. in which one of the two will expire next year. Many reservoirs have been set up to help collect rain water. Recently, a new local water catchment area has been set up, known as the Marina Barrage. It acts as a tidal barrier that prevents high tides from flooding inland low-lying areas while at the same time creating a fresh water reservoir. Planning are currently being carried out by the PUB in which their main purpose is to further collect stormwater from suburban new town developments as well as collect surface overflow of water from insignificant highly urbanized catchments.
By Gerard Heng (14)
1.
ReplyDelete1. Distillation requires boiling to obtain pure water, thus, there will be a high usage of electrical energy. This will cause harm to the Earth as more fossil fuel (non-renewable source of energy) is required to produce the electrical energy needed. Reverse osmosis uses lesser electrical energy, which makes it more efficient and eco-friendlier than Distillation.
If Singapore uses the Distillation method, it will need to purchase the imported fossil fuel from other countries. This means that more money is needed to purchase the fossil fuels. This also means that it will increase Singapore reliance on foreign supply, which contradicts to Singapore's aim.
2. Time is also a issue. Distillation requires a longer time than Reverse osmosis before it is able to collect the distillate. The shorter the time, the faster it is able to supply to the population of Singapore.
3. Reverse osmosis is capable of processing a larger volume of water (in one complete process) than Distillation. (more efficient than Distillation)
All in all, Reverse osmosis has more advantages compared to Distillation. Thus the government prefer this method.
2.
1. Supply provided by water catchment areas - eg The construction of Marina Barrage.
2. Imported water supply - eg Singapore signed contract with Malaysia.
3. Recycled Water - eg The production of NEWater
4. Desalination - eg Reclaiming water from the sea
By Edmund Mong (7)
zhang song (37) 3a
ReplyDelete1.Distillate fuel needed to heat, so that waste of resources. If the use of fossil fuels will cause environmental pollution. The use of reverse osmosis method can not only save resources, but also reduce environmental pollution.
2.Singapore has taken a lot of water-saving strategy. One of them is carrying water from the neighboring countries. Singapore also has a rainwater recycling system is U of Singapore, water can be supplied.
This comment has been removed by the author.
ReplyDeleteFirstly, Singapore uses reverse osmosis because it is clean and earth friendly as no harmful gases are discharged into the atmosphere unlike distillation will give out harmful gases.
ReplyDeleteAlso Reverse osmisis is cheaper and require little energy unlike the Distillation where it require lots of electricity and fuel to boil the water which will be very expensive and it will cause a strain on Singapore financial side.
Also there are limited land as they cannot build any of the distillate factories near the housing district as it could easily cause diseases like cancer etc. However for Reverse osmosis they could actually build it near the housing district as it is not that harmful.
1) Singapore buys water from Malaysia
2) Singapore has many water catchment area to store their water just in case when they have water shortage
3) NEW Water, they recycle used water into drinkable water
4) Distillate Seawater, It is to remove the salt in the sea water and make it into pure water
1. Singapore uses reverse osmosis and not distillation to obtain pure water from seawater because distillation involves lots of fossil fuels to be burnt which causes air pollution. Fossils fuels like oil which is not readily available in country like Singapore, will also have to be bought from other countries causing the water produced to be very expensive. Distillation is also not as efficient in removing chemicals unlike reverse osmosis. The amount of time also affects the rate of production. Hence the government preferred reverse osmosis as it has more advantages compared to Distillation.
ReplyDelete2.
a. Building water catchment areas to collect rainwater.
b. Importing water from Malaysia.
c. NEWater is the recycling of wastewater that has been purified by using various technologies.
d. Building desalination plant which removes salt content in seawater.
Q1)
ReplyDeleteFirstly, I think that by using reverse osmosis, it saves the Singapore government a lot of money by preventing the use of gas to burn the seawater to obtain pure water. As fossil fuels are depleting day by day and thus getting more extinct, I think that by using reverse osmosis is a great solution as we can prevent the usage of fossil fuels in obtaining water and instead use it for other purposes such as generating electricity for instance. However, I think I that we still should not take it for granted and save electricity for example in any way we can to slow down the process of the depletion of fossil fuels as much as possible.
Secondly, I think reverse osmosis saves the Singapore government a lot of time as it does not require any gas to keep heating the seawater and waiting for the seawater to evaporate. This is also an advantage to the Singaporean population as because of the increasing population at hand due to more foreign talent migrating into Singapore, pure water must be obtained even more quickly to quench the thirsts of the increased number of people.
Q2)
Firstly, one strategy taken by Singapore was to built catchment areas. There were many projects executed to do this. Examples of these projects were the Kranji-Pandan Scheme, the Upper Pierce Project and the Western Catchment Water Scheme, which were executed at around 1960-1970. As Singapore developed further, more catchment areas were built and by 2001, there were 19 raw water reservoirs, 9 treatment works and 14 storage or service reservoirs locally to serve domestic needs. The most recent project completed was the Marina Bay reservoir which increased the rainfall catchment to two-thirds of the country's surface area from one half.
Secondly, another strategy taken to increase the supply of water in Singapore was to import water from other countries such as Malaysia. Unfortunately, the two water agreements that supply Singapore this water are due to expire by 2011 and 2061 respectively and the two countries are engaged in a dispute regarding the price of water.
Thirdly, Singapore has also decided to recycle water to increase self-sufficiency in its water supply. NEWater is the brand name given to reclaimed water produced by Singapore's public utilities. More specifically, it is treated wastewater (sewage) that has been purified using dual-membrane (via microfiltration and reverse osmosis as mentioned above) and ultraviolet technologies, in addition to conventional water treatment processes. Producing about 32 million US gallons of water per day, the four NEWater factories located at the Kranji, Seletar, Bedok and Ulu Pandan Water reclamation plants can meet 15% of the whole Singapore population's water needs.
Fourthly, Singapore has also taken the measure to desalinate water. Desalination is the process whereby salt is extracted from seawater by forcing it through plastic membranes and hence helps Singapore obtain pure water.
Last but not the least, every one of us as Singaporean citizens as well have to play our part in saving water instead of just purely relying on the government to obtain water for us. There have been many campaigns to encourage people to save water set up by the government, aiming to reduce the consumption of water for each person everyday. Such ways include, reusing water from washing dishes to water plants if one has any at home and taking a shower instead of a bath to save water. However, with so many campaigns set up, whether do we Singapore citizens take note and carry out any of these water conserving activities seriously is another matter to be questioned.
In general, I do also share the same views as the government for everyone to play a part in saving water and hence I also strongly encourage everyone, not only Singaporeans, to save water as this is not only a national matter but also a global issue as this concerns the whole human race.
By: Reynold Chia (4) 3A
1. Distillation uses up fossil fuels. Fossil fuels is very expensive. Distillation takes up lots of time and sea water contains impurities which some may boil at the same temperature as water. Reverse osmosis filter the water leaving the impurities and other substances away.
ReplyDelete2. 3/4 of Singapore is water catchment areas and Singapore is building Marina Barrage. Singapore still has 2 agreement with Malaysia though they will expire in 2011. Singapore also has a desalination plant which also supply to part of Singapore's water needs. NEWater is also another way that Singapore uses to increase the water supply.
~Clement Tan (6)
1 Firstly,Singapore is country that has to buy resourses from other countries,so distillation is extremely expensive for the government.
ReplyDeleteSecondly,distillation can cause a lot of
smoke ,which means causing environmental problems.
Thirdly,it takes a lot of time to
distill such a huge sum of water.in order to prevent the city in short of water,it is so much better to use reverse osmosis.
2 I think the most important and necessary strategy that Singapore has used is to research
the new technology.For this main reason ,Singapore has become more and more independent in water.The recycling of water is also another strategy that helps the government a lot.It reduces the pressure of water shortage.
1. Distillation is a time consuming and costly process. It requires a heating source which comes from fossil fuels. Fossils fuels are depleting at an increasing rate and the price of fossil fuels is also going up. By using distillation to obtain pure water from seawater, the price of water would go up. The burning of fossil fuels would also contribute to air pollution. Reverse osmosis on the other hand is energy efficient, pollution free and does not produce or use harmful chemicals.
ReplyDelete2. Singapore mainly made use of technology to diversify its water resources. Examples are NEWater and tuas desalination plants. Also, it has built many water catchment areas and reservoirs to store rainwater.
By: Wan Liang Xiang(32)
Q1. Distillation is not used in Singapore to obtain pure water because firstly, the cost of using distillation would be very high. Burning of the fossil fuels required for this process would need a lot of heat energy. Plus, the heating takes up a lot of time and a lot of fossil fuel would be used. Thus, the cost needed for this process would be very costly. Secondly, Singapore is a country which do not have its own fossil fuel and it is better to use reverse osmosis. The amount of money needed to purchase fossil fuel from other countries would also be expensive as fossil fuels are a non-renewable source of energy. Therefore, reverse osmosis is chosen over distillation as reverse osmosis requires less cost and time. It is also an easier process and no burning, which causes air pollution, is needed for this process unlike distillation. Reverse osmosis is also more environmentally-friendly and save the Earth's natural resources as well.
ReplyDeleteQ2. Singapore, on the other hand, also purchases water from neighbouring countries like Malaysia. Reservoirs are also built in Singapore to collect rainwater that would later undergo treatment to obtain pure water for use later.
Jonan Siak (29)
1) Distillation requires large amount of heat energy to evaporate the water in order to get clean drinkable water. Thus, large amount of fossil fuel, which are non-renewable, are burn to obtain clean water. Burning of fossil fuel also requires large amount of oxygen and produce large amount of carbon dioxide, which is harmful to Earth. As a result, Distillation is replaced by reverse osmosis as reverse osmosis is more environmentally friendly.
ReplyDelete2)-Singapore import water from Malaysia
-Water catchment areas are build to collect
rainwater
-NEWater. Sewage was treated to produce clean
drinkable water
-Desalination
Chen Xi(2)
1.
ReplyDelete"Reverse osmosis is similar to the membrane filtration treatment process. However there are key differences between reverse osmosis and filtration. The predominant removal mechanism in membrane filtration is straining, or size exclusion, so the process can theoretically achieve perfect exclusion of particles regardless of operational parameters such as influent pressure and concentration. RO (Reverse Osmosis), however involves a diffusive mechanism so that separation efficiency is dependent on influent solute concentration, pressure and water flux rate [1]. It works by using pressure to force a solution through a membrane, retaining the solute on one side and allowing the pure solvent to pass to the other side. This is the reverse of the normal osmosis process, which is the natural movement of solvent from an area of low solute concentration, through a membrane, to an area of high solute concentration when no external pressure is applied." This is picked from Wikipedia.
As reverse osmosis is a simple process which only consists the movements of solvent and solute due to pressure, while distillation requires a larege amount of fuels to produce heat energy in order to evaporate the water and Singapore is not a very resourceful country, hence reverse osmosis is a more preferable way to obtain pure water from sea water.
2.
Singapore water supply is obtained from rainfall which is collected in reservior and other water catchment areas, imported water from Malaysia, recycled waste water, purification of sea water and produced via desalination. Singaporeans are encouraged to converse water resource too in order to ensure the suffiency of water supply in future.
Khoo Peck Seng (18)
1)
ReplyDeleteReverse osmosis is a form if filtration. so in this case, we are comparing filtration and distillation, in which distillation is the only one using gas. Reverse osmosis does not use gas or fossil fuels in its process unlike distillation, which uses fossil fuels.
Firstly, Singapore does not have fossil fuels as natural resources, thus, to get fossil fuels, we have to buy it from other countries which costs money. If we were to use distillation, then we will need to pump in money every now and then to keep buying fossil fuels from other countries. However, using reverse osmosis, we need only electricity, which is much cheaper the fossil fuels, and can be generated through natural energy, which is clean.
Secondly, Reverse osmosis, compared to distillation, takes a shorter period of time to process and treat water thus, saving time while producing more clean water at the same time.
2)
The main strategy now is using water catchment areas which collects rainwater and purifies it before it is distributed to households. It is the best form of getting water as Singapore is located very near the equator which has abundant rainfall all year round. The Marina reservoir is a more recent and more advanced reservoir which cordons off a small section of seawater from the sea. Rainwater will eventually flush away the seawater and is then turned into a reservoir. Other small strategies are NEWater which uses reverse osmosis to treat and recycle household water. Desalination to treat seawater, also using reverse osmosis.
1.Using distillation as a method to obtain pure water from sea water is absolutely not the wisest thing to do if there is the existence of reverse osmosis. Global warming and lacking of natural resources are becoming two of the most serious problems which the world is facing nowadays. Thus, if we still use distillation method which needs a large sum of burning fuels and resources, the presence of carbon dioxide will simply increases. Moreover, it will hasten the dwindling of the resources. On the other hand, reverse osmosis is a process which occurs filtration to treat water and hence it causes nothing harmful to the environment.
ReplyDelete2.Singapore has tried lots of ways and solutions to solve the water problems and all of them work quite efficiently.
*Importing water from Malaysia.
*NEWater treatment.
*Numerous water catchments are built.
*Reverse osmosis plant.
The only thing which may not be too confident and confirmed is the imported water from Malaysia. In case anything happens in Malaysia and Singapore can`t get enough water supply. Hence, Singapore still needs to exploit more ways of getting pure and clean water.
From
Goh Chen Gang
Suggest possible reasons why Singapore decided to use reverse osmosis and not distillation to obtain pure water from seawater.
ReplyDeleteWhat are some of the strategies that Singapore has taken to diversify Singapore's water resources?
1. Desalination (or multi-stage flash distillation) requires a large amount of two different resources that Singapore lacks, land area and burnable fuel. The land area is required for massive tanks to boil, condense and collect the brine water from seas. Singapore lacks any natural gas resources, therefore it is not economical to buy gas just to purify water. It is not very efficient at purifying water as some concentrated waste water must be discharged as well.
One good point of this form of distillation is that it can be used to simultaneously cool a power plant by using the heat produced by it, hence saving energy, but we do not have that kind of need.
Reverse Osmosis (actually also a kind of desalination), uses pressure to force water molecules through a very fine membrane, which is different from naturally occurring osmosis, hence "Reverse" Osmosis. This requires energy to do so, but it should be considerably less than distillation as electricity instead of fuel can be used. The water obtained is high quality and little wastage is obtained. Hence, this reverse osmosis was a economical yet good choice. Singapore uses RO to treat seawater and wastewater.
However, Reverse Osmosis also has is disadvantages. One is that a lot of pretreatment is required before the wastewater can be run through the RO membrane, this uses UV rays and microfiltration. Two is that a lot of maintenance is required to run the RO plant.
2. Singapore has 4 sources of water that it obtains from.
> Imported water from Malaysia
> Catchment area water from reservoirs and storm water drains
> neWater (Reverse Osmosis)
> Desalination
Singapore's PUB is aiming to find new ways of obtaining water to reduce dependancy on other countries for our growing water needs. What Singaporeans can do is to just conserve water!
1) Singapore has decided to use reverse osmosis as it is eco-friendly as it does not produce any harmful chemicals that may cause harm to our environment. Little amount of power is needed to carry out this process and it does not require as big a land space that Singapore does not have. Reverse osmosis also fully removes dissolved minerals and contaminants that causes water to smell unpleasant, taste poorly and take on unusual colours etc.
ReplyDelete2) Singapore has 4 main sources of water:
-Water catchment areas (E.g. Resevoirs)
-Imported water from other neighboring countries (E.g. Malaysia)
-NEWater
-Desalination
In addition, we can help save water at the same time as these main sources of water, like imported water, for Singapore may run out in the near future.
By: Ekaphat Mathiprechakul (8) 3A
1)Reverse osmosis is cheaper compared to distillation as distillation requires more energy for heating up the seawater, furthermore, distillation requires fuels for burning to produce heat and it leads to more pronounced greenhouse effects due to the release of carbon dioxide during combustion. Reverse osmosis is also more efficient in terms of volume of water it purifies than compared to distillation.
ReplyDelete2) Singapore uses water catchments, water recycling, desalination and importing of water from Malaysia to diversify Singapore's water resources
1.
ReplyDeleteFirstly,reverse osmosis is more earth-friendly than distillation.Because distillation requires a number of energy,such as fuels for burning.That will produce a lot of harmful gases and greenhouse gases like CO₂.Secondly,distillation is more expensive than reverse osmosis.So it can save much money for domestic finance.
2.
Singapore government has been importing water from Malaysia for some years.Besides,Singapore uses water desalination,reverse osmosis,water catchment,water recycling to diversify Singapore's water resources.
1. Distillation needs much fossil fuel. It cost a lot and is not good for the environment. Reverse osmosis is different. It can obtain drinking water from seawater by using membrane. It's not only faster but also cheaper. It can also reduce the emission of greenhouse gases.
ReplyDelete2.Singapore import water from Malaysia and use reservoir to provide drinking water. Singapore also uses recycled water.
1. Reverse osmosis does not require the burning of fossil fuels to generate heat compared to distillation. The burning process also requires an abundant amount of fossil fuels which will be costly since Singapore has no natural resources and crude oil is becoming more scarce. Since reverse osmosis does not require burning, it does not emit carbon dioxide therefore it does not contribute to Singapore's carbon dioxide emission thus not affecting Singapore's participation in the kyoto protocol.
ReplyDelete2. Singapore has 4 national taps / resources of water. Singapore imports water from malaysia and has catchments collect rain water.
Done by : Aaron Chow 3A (5)
1. Distillation requires heating which needs fossil fuels to be burnt. the process of heating the water take a lot of time, and hence makes it a problem to use distillation for part of the countries water resource. Since Singapore does not have natural resources like oil or other fossil fuels, we would have to purchase fossil fuels from other countries and this makes distillation very costly.
ReplyDelete2. Singapore uses the following ways to provide water for the country
- an agreement with malaysia to buy water from them
- many water catchment areas
- NEwater
- Desalination
Many areas are supplied with hard water meaning that your domestic water will contain minerals, iron and other impurities. water softeners
ReplyDeleteater