Stop Water Conservation Now: Desalinization and Its Benefits, Research Paper Example

Abstract: Water Conservation is the one of the current and most important dialogue among environmentalists, as well as the common people. It is a well sustained concept that has been advocated in the minds and hearts of the Americans, not only by all component civic authorities- but by the media and the environmental scientists all over the world. The habit of saving precious water is also being taught to children in schools and in Cartoon channels- this joint movement of the masses implies that people have grown weary and extra cautious about water conservation. My question is why is water conservation becoming such an acclaimed issue when we have enough water in our oceans and seas? We have enough water in our planet in the form of oceans; and according to statistical data the oceans occupy nearly 71% of our earth’s surface and more than 97% of all our planets’ water is contained in the ocean. Thus we are fighting over the 3% of the water and its preservation. Why don’t we stop the huge expenses incurred in educating water preservation, and look at the desalinization of water? (http://www.savethesea.org/STS%20ocean_facts.htm).

Many of us are aware of the word “water conservation” But do we know in spite of the wide range propaganda and $1 trillion having been spent on water compliance issues over the last 30 years: about 50 million Americans are exposed to the danger of drinking unsafe water; about
one-half of the major watersheds in U.S have grave water quality issues; more than one half of the communities do not work in accordance to CWA or CSO laws; about 280 million Americans live in the close proximity of polluted waterways. So instead of shouting for water conservation more emphasis should be given for clean drinking water. (www.waterworld.com) Global water shortages have reached crisis levels, especially in the developing world where 98 percent of water-related deaths occur. There is clearly a need for a long-term, sustainable solution, and we are grateful to have the opportunity to speak at the U.N. to deliver this critically important message,” said G.G. Pique, president and CEO of Energy Recovery Inc.

According to Samuel Taylor Coleridge’s – The Rime of the Ancient Mariner, “Water, water, everywhere, And all the boards did shrink; Water, water, everywhere, Nor any drop to drink.” Well, this is the tragedy of sea water – its is not fit for human consumption due to its salinity. Let us understand the physical difference between sea water and fresh water. According to the Physics Factbook, by Glenn Elert, “The physical properties of seawater to be quite different from those of freshwater because of the presence of various salts make seawater undrinkable. The total dissolved salts in seawater are approximately 34.4 g/L, some 300 times that of river water. The main dissolved constituents in seawater include sodium and chloride. Since salt ions are heavier than water molecules, seawater is denser than freshwater. The density of seawater ranges from 1020 to 1030 kg/m³ while the density of freshwater is about 1000 kg/m³.”  It is thus clear that sea water cannot be used as drinking water unless it is treated. Now water requirement is increasing in leaps and bounds in every consecutive day. It increases pressure on fresh water from rivers and lakes; and it becomes extremely valuable resource, as its volume is not indefinitely exhaustible. It further increases and accentuates in the summer months- and thus water shortage and scarcity increases. It is the best way out to use the inexhaustible sea water as an alternative to drinking water. (http://hypertextbook.com/facts/2002/EdwardLaValley.shtml)

Background for Desalination: In the 4^th century B.C., Aristotle first thought of using membranes to filter salt from seawater. But the actual process of desalination was carried out when seawater was boiled to remove the salts and get fresh water. Around 200 A.D., the sailors started the process of desalination with the help of broilers in the ships.  Since 1950, there has been development of successive membranes just like Aristotle thought, which is now known as reverse osmosis. Gary Crisp, an engineer for the Water Corporation of Western Australia, says “In the last ten years, seawater reverse-osmosis has matured into a viable alternative to thermal desalination,”

Desalinization is often misinterpreted as being the removal process of sodium chloride (salt) from sea water. However, with modern technology it can be better described as a process that can eliminate any mineral or organic or biological chemical substances. It can also be referred to as purification or de-mineralization of water.  The Desalinization process use some basic type of technologies to provide fresh water from sea water: Reverse Osmosis, Electro dialysis, Distillation and Ion Exchange. Reverse Osmosis: It works in a process in which seawater is allowed to pass through a semi permeable membrane; in this way the membrane blocks the salt and minerals and in the same time allows the flow of water molecules. Distillation: In this process the sea water is heated to produce steam. Thus the excess salt and mineral evaporate and the water is condensed with a law salt as well as low level of impurities. Thus the final product might be high quality fresh water, ranging from 1 to 500 parts per million dissolved solids, fit for consumption.

The benefits of desalinization: Presently between 10 and 13 billion gallons of water are being desalinated worldwide per day, which accounts to only about 0.2 percent of global water consumption. However the number is increasing and according to Stephen Gray of Victoria University, “There is significant growth in desalination capacity throughout the world, and it is anticipated to continue for sometime”. Desalinization produces Potable Water. It is the process of removing salt, chemical compounds and minerals from impure water, and has been used as limited source of potable water for some of the communities in California. The basic issue is to desalinize the ocean water to places like San Diego and other coastal and island places where the ground and/or surface water supplies have been eliminated or largely reduced. Water shortages may occur because of limited water sources, droughts, salt water intrusion or contamination and there is scarcity of water even after long phases and dialogue over water conservation measures. Thus desalinization is the only way out when water supplies are reduced or diminished. The government and the civic authorities realize their importance in severe drought or extreme conditions. It is seen that the authorities shout at the top of their agenda about water conservation but employ little effort and planning in desalinization process which could bring an end to the regular qualms for water. Thus the major benefits of desalination are:

• It is the only alternative to survive during shortage of water supply during droughts
• It protects the underground water aquifers from the intrusion of seawater damage
• Provides flexible and reliable source of water
• Protects hygiene, public health, safety and the economy

(http://resources.ca.gov/ocean/97Agenda/Chap5Desal.html)

Why do you think the government of San Diego should opt for desalination more seriously?

San Diego is situated in the semi arid region of the south western part of United States. Here rainfall is minimal and erratic and water is scarce. The San Diego Water Authority, imports 90 percent water from the Colorado River and the Northern California. The rest of the water comes from other sources like the local surface water, groundwater, conservation and recycled water. It is entirely dependent on borrowed reserves. However, the Pacific Ocean is the only source of San Diego which can solve its water problem. A desalination project will provide Carlsbad as well as San Diego County water authorities’ complete control over a local supply of fresh water which will be independent of rainfall and other external resources.

Why Are the Authorities so Apprehensive About Desalination?

The government and the civic authorities are trying hard to cope to the water scarcity and are spending in millions in television adverts and promotions without giving much emphasis to the desalination process. They have been continuous in their strategy for the past 50 years. However, some progress has been made recently and the Australian crisis for water had opened the eyes of the American authorities. It is argued that in spite of the new technological advantages of desalination and other affordable and cheap system infrastructure, there is a huge involvement in the cost of planning; concentration management and permitting are quite high in comparison to other alternatives. Moreover the authorities are worried about the reliability, water quality and the environmental issues that loath them and make them anti desalination. To understand the financial implications of the process of desalination, let us find out the processes involved.

Reverse Osmosis

Reverse Osmosis also known as Membrane Filtration had been seen with as expensive and complex process. However, the technological advancements and 15 years of research have transformed it into a user friendly, mature and reliable technique for purifying water. According to Lenntech, Water Treatment Solution provider, “To desalinate water, we must create a flow through a membrane, causing the water to leave the salty side of the membrane, flowing into the unsalted side. To achieve this, pressure must be created upon the water column on the salt side of the membrane; firstly, to remove the natural osmotic pressure and secondly, to create extra pressure on the water column, in order to push the water through the membrane. For the desalination of seawater, the pressure must be about 50-60 bars.” The Reverse Osmosis is the most effective and economic process of desalination as involves lower cost and lower usage of energy. ( http://www.lenntech.com/desalination-ro-modules.htm#ixzz0XuyBA8VV)

Electro dialysis: In electro dialysis desalination process for seawater, first the seawater is collected and heated by solar energy; and to separate the residue into a diluted solution and concentrated brine; the advantage of electro dialysis is due to the fact that it uses solar energy instead of electric power.

Distillation

It is a phase separation method where the saline water is heated, this in turn produces water vapour which is then condensed to produce freshwater. The various distillations that are used to produce potable water are: MSF, VC, MED and waste-heat evaporators. All of these processes operate on the principle of reducing the vapour pressure of water, within the distillation unit so as to allow boiling to occur at lower temperatures…so that excess heat is not required.

Costs Involved in the Desalination

The Relative and Absolute Costs  estimated in San Diego, the expenditure incurred to bring the water from North Carolina is huge, and the recurring cost as well is more. Again a desalination plant is also expensive, but it will secure free flowing water and remove the dependence on the Colorado River. A comparative analysis of estimated urban water conservation and desalinisation shows:

Urban Water Conservation

Sources: LAEDC, City of Santa Monica

Sources: LAEDC, City of Santa Monica

The data from the analysis reveals that the mighty Metropolitan Water District of Southern California agreed to pay up $14 million per year – or $350 million over the next 25 years, to get a constant supply of water of desalinated water in San Diego. The desalination plant in Carlsbad will be constructed and owned by Poseidon Resources LLC.

The Extra Costs of Desalination

Desalination plants consume a high proportion of electricity. This electrical energy is used to force high pressure on sea water so that it enters through the membranes, and filter out as fresh water. Desalination is ideal along the coastline with easy access to electricity and sea water. Thus desalination is worthwhile in abundance of sea water and electricity. For example, Middle East is heavily dependent on desalinated water. As energy costs fall, desalination costs will also be reduced. MWD offers subsidy to the water produced from desalination plants, estimates that these plants have a potential to provide 150,000 acre feet per year of fresh water. The proposed Poseidon project is estimated to supply 56,000 acre feet per year of fresh water.

Reliability: Ocean distillation is the only solution to drought prone areas. The price is high but it provides unlimited water supply.

Location: If the desalination plants are located next to the ocean, then it can be prevented from the objections of the local property owners. Moreover the brine, which is the by product of desalinization, will flow directly to the ocean and the proximity of the power plant will help to make the brine diluted as it is removed from the power plant.

Greenhouse Gases: Desalinization and distribution of water requires immense energy to operate; and if the source of energy is the fossil fuels then it aggravates the danger of greenhouse emissions.  However, if the sources of energy are wind turbines, as in Western Australia…then much of the concern of greenhouse gases are reduced. If the inland water system is developed to distribute the water, instead of putting pressure on the desalination plant…then also a major part of the energy is saved.

Thus in the face of growing population, intense droughts and climatic change – desalinated water is the most viable option. However, price may be on the higher side- depending on the local energy rates 1, 0000 gallons of water that has been desalinated would cost around $3 to $4. This might seem more apparently in the current situation, but as more and more population increases with high demand and less supply of fresh water; the price of natural water will soar high making desalinated water as an attractive option. (http://waterwebster.com/documents/SCLC_SoCalWaterStrategies_000.pdf)

New Areas of Research

The number of desalination plants is growing worldwide with more than 15,000 units already in place. There is also a continuous research program to initiate further developments and to ploy newer technology to minimize cost and environmental hazards…and to maximize production. There are incessant strategically implemented transformations and technical innovations to make it more affordable. Recently, the largest Australian scientific research agency has joined in collaboration with nine other major universities in an extensive membrane research program to reduce the energy and maintenance costs involved in the process. “Lowering the energy required for desalination and the fouling propensity of membranes are the two biggest challenges facing desalination. A team of diverse researchers will try to tackle these problems by developing new types of membrane materials. The goal is to cut in half the energy required for desalination. We would hope to have something available within the next 10 years,” Gray said.

Water is one of the most abundant resources on planet Earth, yet we are to believe that even with this abundance there is not a drop fit for human or agricultural consumption. The masses of the human population have been told to close their eyes and just believe we are in a desperate and no win situation. There are many promising answers however in the works to reduce the cost of making water fresh and clean for human consumption. As pondered on by World Bank Institute, “Water is essential for all dimensions of life.  Over the past few decades, use of water has increased, and in many places water availability is falling to crisis levels. More than eighty countries, with forty percent of the world’s population, are already facing water shortages, while by year 2020 the world’s population will double. The costs of water infrastructure have risen dramatically. The quality of water in rivers and underground has deteriorated, due to pollution by waste and contaminants from cities, industry and agriculture. Ecosystems are being destroyed, sometimes permanently. Over one billion people lack safe water, and three billion lack sanitation; eighty per cent of infectious diseases are waterborne, killing millions of children each year.” Do you think we should still sit down and scratch our head in calculations over water conservation and desalination?

Reference

Desalination: A National Perspective, (2008) By National Research Council (U.S.). Committee on Advancing Desalination Technology

Birkett, J.D. (1987). “Factors Influencing the Economics of Desalination.” In Non-Conventional Water Resources Use in Developing Countries. New York, United Nations, pp. 89-102. (Natural Resources/Water Series No. 22)

Boari, et al. 1978. “R.O. Pilot Plants Performance in Brackish Water Desalination.,” Desalination, 24, pp. 341-364.

Buros, O.K. 1987. “An Introduction to Desalination.” In Non-Conventional Water Resources Use in Developing Countries. New York, United Nations, pp. 37-53. (Natural Resources/Water Series No. 22)

Cant, R.V. 1980. “Summary of Comments on R.A. Tidball’s ‘Lake Killarney Reverse Osmosis Plant.”‘ In P. Hadwen (ed.). Proceedings of the United Nations Seminar on Small Island Water Problems, Barbados. New York, UNDP. pp. 552-554.

Childs, W.D., and A.E. Dabiri. 1992. “Desalination Cost Savings or VARI-RO.” Pumping Technology, 87, pp. 109-135.

de Gunzbourg, J., and T. Froment. 1987. “Construction of a Solar Desalination Plant (40 cum/day) for a Caribbean Island,” Desalination, 67, pp. 53-58.

LAEDC Consulting Practise http://www.scwd2desal.org/Page-Need.php