Sign in or 
Share this
Water Power!
Title: Water Power - Collection and Purification technologies
Authors: Malini Vangipuram and Pauline Poysophon
Image:
Technology Summary:
Water collection Techniques are specific to the environment conditions one lives in. The focus is given to different collection technologies (for different environments) and on UV Wateworks, a simple and effective technology to purify water
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Why is water important?
Water is a necessary element of life and comprises approximately 50-60% of our body, depending on age and sex. Gobal water shortag impacts not only world health and sanitation but also the political and social spheres. Historically the control of water resources by both state and non-state actors have fostered tension and have been used both as a tool for military and political action as well as terrorism. An example includes a case in 1984, when a members of the Rajneeshee religious cult contaminated a city water supply in The Dalles, Orgeon, using Salmonella. A community outbreak of over 750 cases occurred in a country that normally reports fewer than five cases per year. In 1991, Baghdad’s modern water supply and sanitation system were intentionally and unintentionally damaged by Allied coalition – “Four of seven major pumping stations were destroyed, as were 31 municipal water and seweage facilities – 20 in Baghdad, resulting in sewage pouring into the Trigrs. Water purification plants were incapacitated throughout Iraq.” In the first 8 months of 1991, after Iraq’s water infrastructure was damaged by the Persian Gulf War, the New England Journal of Medicine reported that nearly 47,000 more children than normal died in Iraq and the country’s infant mortality rate doubled to 92.7 per 1,000 live births. Furthermore, water is also important for the following reasons:
· Irrigated water allows the development and maintenance of agriculture and various sectors of the economy.
· Water is necessary for sanitation and preservation of the health and well-being of individuals, qualifying as a legal human right in some countries. The Bill of Rights in the new South Africa Constitution, adopted in 1994, Section 27(1)(b) states: “Everyone has the right to have access to sufficient food and water.”
However, a large number of individuals in the global population have no access to safe drinking water. Given this fact, we analzye both methods of water collection and water purfication as means to provide safe drinking water. Note that these methods are not discussed separately and should be considered as solutions to a multi-faceted plan which utilizes many methods to solve water shortage problems in a complete and balanced way.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
Water Locations on Earth
Figure 1: Distribution of Earth’s Water.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Mechanisms for Water Collection
A. Extracting Groundwater
Extracting water via pumps relies on the presence of groundwater which collects in layers of permeable rock and unconsolidated materials (i.e. gravel, sand, silt, or clay). These aquifers comprise approximately 30% of the world’s supply of freshwater and can be characterized as replenishable or nonreplenishable (fossil) depending on their depth and accessibility to topical rainfall. Technologies which provide access to these water sources have existed for centuries, with the exception of recent 20th century drilling developments that allow the penetration of deep fossil aquifers. Therefore, access to these freshwater sources is not limited by pump technology, but rather by the availability of groundwater, which when depleted limits the maximum pump rate to the rate of recharge. Unfortunately, with increasing global demands for water as a result of industrialization, exponential growth of the human population, and rising demand for hydroelectric power, groundwater levels is decreasing globally. The following examples include of some the world’s water hotspots:
(i) The Ogallala Aquifer accounts for 95% of the United States’ fresh water, stretching 800 miles from Texas to South Dakota, providing for an estimated 1/3 of all U.S. irrigated water. Formed over millions of years, the aquifer has since been occluded from its original natural sources and is being steadily depleted, dropping in some areas by 3-5 feet per year. Estimates for its remaining lifespan vary in different areas, ranging from 60-250 years.
(ii) Mexico City is sinking due to the amount of water being pumped from beneath its foundations. To date it has sunk an estimated 9 meters into the soft, drained lake bed since the 1900s.
(iii) Chinese wheat farmers in some areas are pumping water from a depth of 300 meters (~1,000 feet), raising pumping cost so high that farmers are forced to abandon irrigation. A World Bank study indicates that China is overpumping three rivers basins, the Hai, the Yellow, and the Huai River. Since it takes 1,000 tons of water to produce 1 ton of grain, the shortfall in the Hai basin of approximately 40 billion tons of water/year means that when the aquifer is depleted, the grain harvest will drop by 40 million tons – enough to feed 120 million Chinese.
(iv) In India, 21 million new wells drilled are lowering water tables in most of the country. In North Gujarat, the water table is falling by 6 meters (20 feet) per year. In Tamil Nadu, a state with more than 62 million people in southern India, falling water tables have dried up 95% of wells owned by small farmers, reducing the irrigated area in the state by half over the last decade. As water tables fall, well drillers use modified oil-drilling technology to reach water, doing as deep as 1,000 meters in some locations.
(v) Pakistan, a country with a population growth of 3 million people per year, is mining its underground water due to drops in the water tables in some areas of the fertile Punjab plain. Observation wells near the twin cities of Islamabad and Rawalpindi demonstrate a decrease in the water table from 1-2 meters/year between the years 1982-2000. In the province of Baluchistan, water tables around the capital, Quetta, are falling by 3.5 meters per year and is estimated to be depleted in 15 years if current consumption rates continue.
(vi) Iran, a country of 70 million people, is overpumping its aquifers by an average of 5 billion tons of water per year, the water equivalent of one third of its annual grain harvest. Under the small but agriculturally rich Chenaran Plain in northeastern Iran, the water table was falling by 2.8 meters a year in the late 1990s due to drilling of new wells to supply water for irrigation and the growing town of Mashad. Villages in eastern Iran are being abandoned as wells go dry, generating a flow of “water refugees.”
For fossil aquifers, as the U.S. Ogallala aquifer, the deep aquifer under the North China Plain, or the Saudi aquifer, depletion brings pumping to an end, so that in the absence of irrigation water farmers must return to lower-yield dry land farming if rainfall permits, or end agriculture in more arid regions as the Southwestern U.S. or the Middle East. Even with improvements in pump technology, the depletion of surface ground water is a severe problem only alleviated by costly drilling into deeper water sources using modified oil drilling technology. This reveals that solving the world’s water problems clearly cannot be accomplished via applying a one-method plan centered on well-drilling because even if a cost-effective method for deep-well drilling is developed, non-replenishable water sources are readily depleted given the current consumption rate. In conjunction to tapping ground water sources, considerations must be made to the extraction of freshwater from non-conventional sources or from replenishable sources in a manner that preserves the natural water cycle. Note in Figure 2 the impact of a growing city on the health of a shallow aquifer. As the population of a city grows, there is an increase in ground water pollution as waste from the city and nearby fields seeps back into the water source. As these sources become polluted, the city expands outward using peripheral groundwater sources until depletion forces the import of water from other cities. This means that well drilling in small villages, as exemplified by the undertakings of the Global Water organization, only supplies a temporary solution until the town expands or until water sources are rendered non-potable as a result of contamination. These arguments, however, do not make obsolete new and innovative pump designs which give people access to clean water. Rather it speaks on lessons we’ve learned many times throughout history, that a multi-faceted problem requires a multi-faceted and balanced solution. In addition to well drilling and innovative pump designs, several water collecting mechanisms are available for consideration to be used in conjunction with well drilling. In addition to these mechanisms, one should also consider the extraction of water from the ocean via desalination, a purification method discussed in the following segment of this paper.
Figure 2: Evolution of water supply and waste water disposal.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Rainwater CollectionOverview
The process of rain harvesting relies on both mechanical and natural processes which are limited by the annual precipitation of a given region. Traditionally, rainwater harvesting has been practiced in arid and semi-arid areas to provide drinking and domestic water. However, this practice largely ignores the versatility of rainwater which can be used to supplement the urban water supply to increase soil moisture for urban greenery, to increase the ground water table through artificial recharge, to mitigate urban flooding, and to improve the quality of groundwater. At the household level in developing urban areas, harvested rainwater can be used for flushing toilets, laundry, bathing, and drinking. Note that because rainwater may be contaminated, it is often not considered safe for drinking without further treatment and purification. Rainwater harvested from roofs can contain animal feces, mosses and lichen, urban pollution, inorganic ions from the ocean (i.e. Ca, ,Mg, K, Cl, SO4), dissolved gasses (CO2, NOx, ,Sox), and high levels of pesticides depending on region. Many rain harvesting systems contain a “first-flush” mechanism which diverts initial water flow to waste ensuring that large-particle residues which accumulate on the collection surface are washed away. Generally a rainwater harvesting system is comprised of 3 components: catchment, conveyance, and storage. Figure 3 indicates a schematic drawing of a rain harvesting system, using a roof and fiberglass storage cistern adjusted to divert water from a storage tank to plumbing fixtures; note that in some areas, this system is simplified to exclude both the pump and purification system, as in some regions in Australia. This is particularly advantageous because a rain harvesting system is not limited by high cost since startup material is cheap, readily available, and inexpensive. Furthermore, simplistic rain harvesting systems do not require high levels of assembly skills or pre-existing knowledge of technology.
Figure 3: Example of a Rain Harvesting System
The idea of tapping into rainwater as a resource is especially appealing because its’ yield (depending on regional rainfall) is reasonably large and sufficient for normal human use. For example, 1-inch rain on 1000 square feet of collection surface will yield about 550 gallons of rainwater. Furthermore, the implementation of rain-harvesting has demonstrated success in the states, especially in Texas, as well as other countries, as demonstrated by case studies observed in India.
(i) Rainwater Harvesting in Chennai is facilitated by the creation of a Rain Center, which was created to buffer the burgeoning water needs of an exploding urban population. Chennai (Madras) is one of the four major metropolises of India and the capital of the state of Tamil Nadu, which as iterated in the previous section has experienced a serious depletion of groundwater due to overexploitation. The Rain Center, co-funded by non-resident Indians living the U.S., NGOs head-quartered in New Delhi, and the state government of Tami Nadu, seeks to educate locals about the importance of rainwater harvesting both for immediate uses and for sustaining the water table in the long run. They assist with implementation and construction of rain-harvesting systems by conducting workshops, training programs and providing free, site-specific advice. The Rain Center, in addition carries out field studies on the effective artificial aquifer recharge, the effectiveness of various types of rainwater harvesting structures, and the post-monsoon impact on the quality and exploitable quantity of groundwater.
(ii) In Chamarajpet (Bangalore), a team of women slum dwellers recently formed a Rainwater Club, an organization that has been disseminating information on rainwater harvesting, headed by S. Vishwanath, a water activist of international reputation. They advocate the construction of rain harvesting systems constructed from simple plastic rain barrels and PVC pipes. Rainwater is filtered at the opening of the collection via a sponge filter which can be washed for reuse. A rain barrel can collect a substantial amount of water, given it is emptied every time it rains. Under this assumption (during the rainy season), a 50 sq.m space on the roof connected to a 500 liters rain barrel can collect nearly 23,000 liters of rainwater in a year, under Bangalore conditions. Similarly a 1000 liters rain barrel can collect nearly 35,000 liters of water in a year. In many parts of Kerala with over 100 days of rain annually, a 500 liter barrel can collect around 40,000 litres. The space required for a 500 liter rain barrel is four cubic feet and on average requires approximately 2500 rupees for installation whereas a 1000 liter rain barrel would cost approximately 4300 rupees. Using a hosepipe and a Zero-B type filter, the tap can be connected to the bore well or sump tank for domestic usage at a costs of aproximatley 60 rupees. Overflows from rain barrels can also be used for recharging groundwater, open wells, and bore wells.
RWH (Rainwater Harvesting): Technical Basics
1. To determine the amount of water yield for any RWH system, the basic calculation entails the formula:
Roof Area (square meters) x total annual rainfall (mm) x efficiency factor/runoff coefficient) = annual water supply in liters
2. To determine how much water a family consumes:
(Annual Water Supply)/ [Family size (# of people) x 365 (days/year)] = Liters per person per day
*generally consumption ranges from 50-300 Liters/person/day for drinking, cooking, bathing, flushing, laundry, and gardening
3. Components of a Rooftop System:
Some considerations for storage design and construction should including the following:
C. Collection liquid water from atmospheric water:
Note that the aforementioned rainwater harvesting systems rely rainfall, which with changing climate patterns may become unpredictable and erratic. Because of this, we should analyze systems which can extract water from non-conventional atmospheric sources.
Island Sky vs. Aqua Science Water Extraction System
Aqua Science has developed a water extraction machine that is able to collect water from the atmosphere. The machine works by pushing air through a liquid salt solution of lithium chloride, a hydroscopic compound which attracts water from its surroundings and naturally decontaminates it (excluding inorganic water contaminants). Because the compound used by the machine attracts water molecules and concentrates it, it allows water to be harvested from arid regions as well as humid regions. Their current atmospheric water extraction machines can provide approximately 350-1,200 gallons of water per day with a target price of approximately $0.25 per gallon depending on climate, temperature, and costs of setup and electricity. The benefits include:
Island Sky, an Austrailian based company, similarily devised a machine which also extracts water from the atmosphere. However, their employed a adiabatic distillation process which replicates the natural process where water vapor condenses into liquid water by continuously mimicking the “dew point” using vapor compression. Air is drawn through a specially designed filter that removes dust, purifying water vapors. As water condenses it is then collected in the water storage vessel and is purified with OZONE, an EPA and FDA approved purification system. Unlike like Aqua Science, the Skywater machines are small, personal, and are targeted to replace run-up-the-mill water coolers. Several advantages of Skywater are listed below.
· Skywater 14 is energy efficient and can make a gallon of water as low as $0.16 per gallon for the 110 volt model.
· It requires no plumbing or general assembly and runs on a standard 110 or 220 volt electricity
· Water output performance is up to 14 gallons per day in optimal conditions and 3 gallons per day at 40% relative humidity
· Electrical consumption is 2 kilowatt hour/gallon of water produced in humid conditions for the 110 volt and 220 volt model
However, disadvantages include:
Both Skywater and the Aqua Science Module was intended to generate water fit for drinking, which essentially increases the cost of water produced given the extra cost of filtration and purification . From Figure 5, humans understandably use water for many other functions other than drinking and cooking. In conjunction with these water extraction systems, sustainable water practices may include the use of rainwater for gardening, laundry, and bathing which do not require water purified to drinking standards exclude the higher costs of purification. Although the use of Island Sky can reap enormous benefits for developed countries, where the population can afford to own individual units, it is economically unfeasible for developing countries at its current price given its water output. Conversely, Aqua Sciences, though given its high initial cost, is more adapted to the water needs of developing countries, like India, where a large and concentrated population require a large amount of their water from an artificial source (i.e. a water truck). In this sense, Aqua Science's machine, originally designed for diaster relief, can in part replace the use of water trucks in order to reduce the cost of water transportation.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Other Ideas:
Figure 4: Skywater 14 Water production chart, depending on the variability of temperature and humidity.
Figure 5: Estimated water use for the City of Bangalore
Our next focus is going to be on the Purification of Water
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Why is it important to purify water ?
Before discussing the ways to purify water, it is important to be aware of the present conditions of drinking water in third world countries. About 60% of the households in Patna, India, drink contaminated water. In the last two months, the Patna Water Board (PWB) collected 150 water samples from different parts of the city. After testing, about 45 samples were found unfit for human consumption. These were found containing bacterial contamination, including e-coli. In October, 2000, the arsenic hazard in Bangladesh villages resulted in the accidental poisoning of about 85 million out of its 125 million people. Arsenic contamination is a natural occurring accumulation of highly concentrated arsenic in deeper levels of groundwater. This accumulation of arsenic has increased substantially due to the use of tube wells for water supply in the Ganges Delta. A 2007 study found that over 137 million people in more than 70 countries are probably affected by arsenic poisoning of drinking water. The U.S. Water News published an article in 2003 about the leading cause of cancer in Lucknow, India - the cause is the impure water drunk by over 70% of Lucknow’s population. About 2,300 cancer patients visit King George's Medical College hospital in Lucknow, the state capital, every month. Eight years ago that figure was less than a 1,000.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------
Reasons behind Water Impurity
There are several background reasons to this issue. The biggest being the lack of action by the Government of India. On April 22nd, 2002, more than 2,000 irate protestors gathered at the Hindustan Coco Cola Company in Plachimada, Kerala. Coco Cola’s indiscriminate mining of groundwater [illegally] has mined up many wells and contaminated the remainder. The water was declared to be very hard, as the constant extraction of the water had increased the rate at which the water flows through the limestone or clay. What did the government do about it? Nothing. In fact, rather than attacking the Coco Cola Industry, the protestors were arrested and persecuted. In the absence of any law to regulate the extraction of groundwater, people or companies with resources and money can privatize aquifers just by virtue of owning a small piece of land. Reason Two, In India, a sacred lake is used for many functions such as praying, cleaning, defecating, drinking and cooking. The only purification technique employed is the boiling of water (which is not enough to eliminate all the contaminants). Pollution and industrialization that occurs due to the arising industries in India also add to the misery.
Figure Eight. Water Strike against Coco-Cola Company
Reason Three, the tubes carrying clean drinking water sits most of the time next to the sewage lines. One crack, one break, one monsoon season allows the two to mix and the drinking water becomes contaminated with feces. There are several diseases caused by this sort of contamination – the biggest being vibro cholera. Mosquito-borne diseases are also transmitted through the fecal matter. This explains the lack of eradication of diseases such as malaria. On July 2005, 14 people died over one weekend due to malaria (mainly passed by the contaminated drinking water). So there is no doubt that the situation is severe. However, each of the aforementioned issues can be solved by the implementation of a simple, cost-effective purification technology owned by a private company such as Water Health Technologies [whose mission is to implement the technology to meet the needs of rural villagers].
Figure Nine: Woman walking in the sewage mixed monsoon water
---------------------------------------------------------------------------------------------------------------------------------------------------------------------
Purification Technologies and UV Waterworks
There are many purification technologies that are already in use in many parts of the world. However, their success has not been great. Reverse osmosis ( using pressure to make water go from high concentration to low concentration, thereby separating impure solvents), desalination ( removing salt from sea water), water softening (removing hard metals from water), ultra filtration (using UV rays to filter water) have existed for almost 2 decades. The issue with current technologies is scalability and afford ability - what is needed is a SIMPLE, COST-EFFECTIVE purification technology that can be used by illiterates in rural villages, most of whom earn less than two dollars a day.
One such technology that meets the budget of a rural villager and is extremely simple to use is UV Waterworks (UVW), designed by Dr. Ashok Gadgil. This technology uses an ultraviolet light source suspended in air to inactivate a broad range of microorganisms. However, unlike many other ultra filtration technologies, UV Waterworks needs low maintenance and requires low energy. The instrument inactivates microorganisms by disrupting their DNA processes and so when the pathogens try to replicate, they die.
Figures Ten and Eleven. UV Waterworks designed by Dr.Ashok Gadgil.
The UVW uses only 60 watts solar cell (energy equivalent to one car battery to provide safe drinking water to approximately 2000 people. Gravity powers the flow of water into the UV chamber, deactivating 99.95% of contaminating bacteria and viruses. UVW is a size of a microwave and weighs only 15 pounds. This makes the technology scalable and implementing in any rural, remote area will be easy. The technology requires low maintenance and the unit aims to be completely failsafe. If there is any sort of malfunction, the entire system shuts down and the valve closes, allowing no water to enter the device. The next important question is quantity. Would such a small device be able to purify enough water to meet the demands of a village? Yes. UVW can disinfect water at the rate of four gallons/minute. Roughly 2880 gallons of water can be purified if the device is on for 12 hours each day. Villagers who have extremely low budget income can easily afford the water as UVW gives 1000 gallons for 5 cents. The officers of National Drinking Water Mission in India have determined that 20 cents per person per year is affordable for drinking water disinfection, UVW beats this price without sacrificing the quality of the water. The World Head Organization declares the water to surpass its standards of clean water. So there is no doubt that this technology makes heads turn in all directions, however implementation and acceptance by rural villagers plays a key role in the success of such a technology.
Worldwide, two hundred UVW units have been installed, mostly in Mexico and the Philippines. Approximately 200,000 people rely on UVW just within Mexico and Philippines. UV Waterworks was part of the first integrated community water system in Zihuatenejo, Mexico, located near Acapulco. This station alone provides water for 2000 people each day. In the Philippines, "Aqua Sure" water stations have been established in urban communities, where people can buy UVW treated water for a third of the cost of bottled water. Additionally, the Rotary Club has funded community UVW water centers in many Philippine public schools located in very poor areas of Manila. This technology is also being implemented in many other countries. In fact, the first field testing supported by the Department of Energy was performed in Durban, South Africa. In these tests, UVW was installed at a hospice for abandoned infants, the majority of whom were HIV-positive. Before the installation, approximately half of the children died from AIDS-related complications. Use of the UV Waterworks device significantly improved these children's chances of living with HIV.
Cons of UV Waterworks
After getting in touch with Dr. Ashok Gadgil, it was found that UVW works only on organic pathogens and not on metals. So UVW will no way help in taking out arsenic from the water. This is a big con. Next, the one time payment of $300 for one UVW unit might be too expensive for many villages. If some sort of grant or loan was giving to these villagers, with time they will be able to pay for the unit.
Pros of UV Waterworks
Women, who are usually the water carriers and purifiers, have more time to do other things. Longer lifespan that is made possible by UVW can yield more lifetime savings. People from the village can be trained to maintain the machine (the parts are easy to find in any hardware store) and to run it. Some villagers can market the instrument. UVW can be more than just a clean water provider, it can be the source of revenue for a village! A small price can be charged for the usage of the instrument. Small jobs for maintenance, regulation, distribution and marketing can arise and help the economy in the long run.
Implementation Issues
One of the other biggest barriers faced by UV Waterworks in its implementation in India is its culture. In many parts of India, women sings songs, while fetching the water or while boiling it. The 2 mile walk to get water and the boiling processes has become part of the culture and the fear of technology, itself, serves as a barrier. While boiling the water, women sing songs If the people in the villages that have used UVW market it, the trust of the rural people will be earned and the technology can be implemented.
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Research Links:
ttp://www.gizmag.com/go/4418/globalwater.org
http://www.newsroom.ucr.edu/cgi-bin/display.cgi?id=1219
http://wiki.edc-cu.org/blogs/index.php/videos/2007/12/14/p747
http://www.h2ro.com/_Solutio2.htm
http://dst.gov.in/scientific-programme/t-d-joint-techsys.htm
http://www.news.dow.com/dow_news/feature/2007/07_02_07/index.htm
WaterHealth
http://web.mit.edu/invent/www/ima/gadgil_diag3.html http://www.islandsky.com/ http://www.allatoms.com/WaterBottlePage.htm http://www.sciencedaily.com/releases/2007/06/070604222124.htm http://usmilitary.about.com/cs/armyweapons/a/arwater.htm http://www.wired.com/science/discoveries/news/2006/10/71898 http://www.aquasciences.com/products.html http://americanobserver.net/2006/10/05/florida-company-unveils-disaster-relief-tool-that-plucks-drinking-water-from-dry-air/ http://www.maxwaterdesal.com/projectedoutputs.htm http://www.earth-policy.org/Books/Seg/PB2ch03_ss2.htm http://news.bbc.co.uk/1/hi/sci/tech/3754520.stm http://www.rwh.in/ http://www.indiawaterportal.org/tt/rwh/ http://www.indiatogether.org/2005/mar/env-barrel.htm http://www.indiawaterportal.org/tt/rwh/courses/DebbieRTRWHPresentation.pdf http://www.patp3.webbler.co.uk/doc.php?id=671§ion=14 http://www.teachersdomain.org/resources/ess05/sci/ess/watcyc/rainfall/index.html http://www.abc.net.au/science/news/stories/2007/1860729.htm
http://www.unep.org/dewa/assessments/ecosystems/water/vitalwater/index.htm http://ga.water.usgs.gov/edu/earthwherewater.html http://www.who.int/water_sanitation_health/publications/facts2004/en/index.html
Authors: Malini Vangipuram and Pauline Poysophon
Image:
Technology Summary:
Water collection Techniques are specific to the environment conditions one lives in. The focus is given to different collection technologies (for different environments) and on UV Wateworks, a simple and effective technology to purify water
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Why is water important?
Water is a necessary element of life and comprises approximately 50-60% of our body, depending on age and sex. Gobal water shortag impacts not only world health and sanitation but also the political and social spheres. Historically the control of water resources by both state and non-state actors have fostered tension and have been used both as a tool for military and political action as well as terrorism. An example includes a case in 1984, when a members of the Rajneeshee religious cult contaminated a city water supply in The Dalles, Orgeon, using Salmonella. A community outbreak of over 750 cases occurred in a country that normally reports fewer than five cases per year. In 1991, Baghdad’s modern water supply and sanitation system were intentionally and unintentionally damaged by Allied coalition – “Four of seven major pumping stations were destroyed, as were 31 municipal water and seweage facilities – 20 in Baghdad, resulting in sewage pouring into the Trigrs. Water purification plants were incapacitated throughout Iraq.” In the first 8 months of 1991, after Iraq’s water infrastructure was damaged by the Persian Gulf War, the New England Journal of Medicine reported that nearly 47,000 more children than normal died in Iraq and the country’s infant mortality rate doubled to 92.7 per 1,000 live births. Furthermore, water is also important for the following reasons:
· Irrigated water allows the development and maintenance of agriculture and various sectors of the economy.
· Water is necessary for sanitation and preservation of the health and well-being of individuals, qualifying as a legal human right in some countries. The Bill of Rights in the new South Africa Constitution, adopted in 1994, Section 27(1)(b) states: “Everyone has the right to have access to sufficient food and water.”
However, a large number of individuals in the global population have no access to safe drinking water. Given this fact, we analzye both methods of water collection and water purfication as means to provide safe drinking water. Note that these methods are not discussed separately and should be considered as solutions to a multi-faceted plan which utilizes many methods to solve water shortage problems in a complete and balanced way.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
Water Locations on Earth
Figure 1: Distribution of Earth’s Water.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Mechanisms for Water Collection
A. Extracting Groundwater
Extracting water via pumps relies on the presence of groundwater which collects in layers of permeable rock and unconsolidated materials (i.e. gravel, sand, silt, or clay). These aquifers comprise approximately 30% of the world’s supply of freshwater and can be characterized as replenishable or nonreplenishable (fossil) depending on their depth and accessibility to topical rainfall. Technologies which provide access to these water sources have existed for centuries, with the exception of recent 20th century drilling developments that allow the penetration of deep fossil aquifers. Therefore, access to these freshwater sources is not limited by pump technology, but rather by the availability of groundwater, which when depleted limits the maximum pump rate to the rate of recharge. Unfortunately, with increasing global demands for water as a result of industrialization, exponential growth of the human population, and rising demand for hydroelectric power, groundwater levels is decreasing globally. The following examples include of some the world’s water hotspots:
(i) The Ogallala Aquifer accounts for 95% of the United States’ fresh water, stretching 800 miles from Texas to South Dakota, providing for an estimated 1/3 of all U.S. irrigated water. Formed over millions of years, the aquifer has since been occluded from its original natural sources and is being steadily depleted, dropping in some areas by 3-5 feet per year. Estimates for its remaining lifespan vary in different areas, ranging from 60-250 years.
(ii) Mexico City is sinking due to the amount of water being pumped from beneath its foundations. To date it has sunk an estimated 9 meters into the soft, drained lake bed since the 1900s.
(iii) Chinese wheat farmers in some areas are pumping water from a depth of 300 meters (~1,000 feet), raising pumping cost so high that farmers are forced to abandon irrigation. A World Bank study indicates that China is overpumping three rivers basins, the Hai, the Yellow, and the Huai River. Since it takes 1,000 tons of water to produce 1 ton of grain, the shortfall in the Hai basin of approximately 40 billion tons of water/year means that when the aquifer is depleted, the grain harvest will drop by 40 million tons – enough to feed 120 million Chinese.
(iv) In India, 21 million new wells drilled are lowering water tables in most of the country. In North Gujarat, the water table is falling by 6 meters (20 feet) per year. In Tamil Nadu, a state with more than 62 million people in southern India, falling water tables have dried up 95% of wells owned by small farmers, reducing the irrigated area in the state by half over the last decade. As water tables fall, well drillers use modified oil-drilling technology to reach water, doing as deep as 1,000 meters in some locations.
(v) Pakistan, a country with a population growth of 3 million people per year, is mining its underground water due to drops in the water tables in some areas of the fertile Punjab plain. Observation wells near the twin cities of Islamabad and Rawalpindi demonstrate a decrease in the water table from 1-2 meters/year between the years 1982-2000. In the province of Baluchistan, water tables around the capital, Quetta, are falling by 3.5 meters per year and is estimated to be depleted in 15 years if current consumption rates continue.
(vi) Iran, a country of 70 million people, is overpumping its aquifers by an average of 5 billion tons of water per year, the water equivalent of one third of its annual grain harvest. Under the small but agriculturally rich Chenaran Plain in northeastern Iran, the water table was falling by 2.8 meters a year in the late 1990s due to drilling of new wells to supply water for irrigation and the growing town of Mashad. Villages in eastern Iran are being abandoned as wells go dry, generating a flow of “water refugees.”
For fossil aquifers, as the U.S. Ogallala aquifer, the deep aquifer under the North China Plain, or the Saudi aquifer, depletion brings pumping to an end, so that in the absence of irrigation water farmers must return to lower-yield dry land farming if rainfall permits, or end agriculture in more arid regions as the Southwestern U.S. or the Middle East. Even with improvements in pump technology, the depletion of surface ground water is a severe problem only alleviated by costly drilling into deeper water sources using modified oil drilling technology. This reveals that solving the world’s water problems clearly cannot be accomplished via applying a one-method plan centered on well-drilling because even if a cost-effective method for deep-well drilling is developed, non-replenishable water sources are readily depleted given the current consumption rate. In conjunction to tapping ground water sources, considerations must be made to the extraction of freshwater from non-conventional sources or from replenishable sources in a manner that preserves the natural water cycle. Note in Figure 2 the impact of a growing city on the health of a shallow aquifer. As the population of a city grows, there is an increase in ground water pollution as waste from the city and nearby fields seeps back into the water source. As these sources become polluted, the city expands outward using peripheral groundwater sources until depletion forces the import of water from other cities. This means that well drilling in small villages, as exemplified by the undertakings of the Global Water organization, only supplies a temporary solution until the town expands or until water sources are rendered non-potable as a result of contamination. These arguments, however, do not make obsolete new and innovative pump designs which give people access to clean water. Rather it speaks on lessons we’ve learned many times throughout history, that a multi-faceted problem requires a multi-faceted and balanced solution. In addition to well drilling and innovative pump designs, several water collecting mechanisms are available for consideration to be used in conjunction with well drilling. In addition to these mechanisms, one should also consider the extraction of water from the ocean via desalination, a purification method discussed in the following segment of this paper.
 |
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Rainwater CollectionOverview
The process of rain harvesting relies on both mechanical and natural processes which are limited by the annual precipitation of a given region. Traditionally, rainwater harvesting has been practiced in arid and semi-arid areas to provide drinking and domestic water. However, this practice largely ignores the versatility of rainwater which can be used to supplement the urban water supply to increase soil moisture for urban greenery, to increase the ground water table through artificial recharge, to mitigate urban flooding, and to improve the quality of groundwater. At the household level in developing urban areas, harvested rainwater can be used for flushing toilets, laundry, bathing, and drinking. Note that because rainwater may be contaminated, it is often not considered safe for drinking without further treatment and purification. Rainwater harvested from roofs can contain animal feces, mosses and lichen, urban pollution, inorganic ions from the ocean (i.e. Ca, ,Mg, K, Cl, SO4), dissolved gasses (CO2, NOx, ,Sox), and high levels of pesticides depending on region. Many rain harvesting systems contain a “first-flush” mechanism which diverts initial water flow to waste ensuring that large-particle residues which accumulate on the collection surface are washed away. Generally a rainwater harvesting system is comprised of 3 components: catchment, conveyance, and storage. Figure 3 indicates a schematic drawing of a rain harvesting system, using a roof and fiberglass storage cistern adjusted to divert water from a storage tank to plumbing fixtures; note that in some areas, this system is simplified to exclude both the pump and purification system, as in some regions in Australia. This is particularly advantageous because a rain harvesting system is not limited by high cost since startup material is cheap, readily available, and inexpensive. Furthermore, simplistic rain harvesting systems do not require high levels of assembly skills or pre-existing knowledge of technology.
Figure 3: Example of a Rain Harvesting System
The idea of tapping into rainwater as a resource is especially appealing because its’ yield (depending on regional rainfall) is reasonably large and sufficient for normal human use. For example, 1-inch rain on 1000 square feet of collection surface will yield about 550 gallons of rainwater. Furthermore, the implementation of rain-harvesting has demonstrated success in the states, especially in Texas, as well as other countries, as demonstrated by case studies observed in India.
(i) Rainwater Harvesting in Chennai is facilitated by the creation of a Rain Center, which was created to buffer the burgeoning water needs of an exploding urban population. Chennai (Madras) is one of the four major metropolises of India and the capital of the state of Tamil Nadu, which as iterated in the previous section has experienced a serious depletion of groundwater due to overexploitation. The Rain Center, co-funded by non-resident Indians living the U.S., NGOs head-quartered in New Delhi, and the state government of Tami Nadu, seeks to educate locals about the importance of rainwater harvesting both for immediate uses and for sustaining the water table in the long run. They assist with implementation and construction of rain-harvesting systems by conducting workshops, training programs and providing free, site-specific advice. The Rain Center, in addition carries out field studies on the effective artificial aquifer recharge, the effectiveness of various types of rainwater harvesting structures, and the post-monsoon impact on the quality and exploitable quantity of groundwater.
(ii) In Chamarajpet (Bangalore), a team of women slum dwellers recently formed a Rainwater Club, an organization that has been disseminating information on rainwater harvesting, headed by S. Vishwanath, a water activist of international reputation. They advocate the construction of rain harvesting systems constructed from simple plastic rain barrels and PVC pipes. Rainwater is filtered at the opening of the collection via a sponge filter which can be washed for reuse. A rain barrel can collect a substantial amount of water, given it is emptied every time it rains. Under this assumption (during the rainy season), a 50 sq.m space on the roof connected to a 500 liters rain barrel can collect nearly 23,000 liters of rainwater in a year, under Bangalore conditions. Similarly a 1000 liters rain barrel can collect nearly 35,000 liters of water in a year. In many parts of Kerala with over 100 days of rain annually, a 500 liter barrel can collect around 40,000 litres. The space required for a 500 liter rain barrel is four cubic feet and on average requires approximately 2500 rupees for installation whereas a 1000 liter rain barrel would cost approximately 4300 rupees. Using a hosepipe and a Zero-B type filter, the tap can be connected to the bore well or sump tank for domestic usage at a costs of aproximatley 60 rupees. Overflows from rain barrels can also be used for recharging groundwater, open wells, and bore wells.
RWH (Rainwater Harvesting): Technical Basics
1. To determine the amount of water yield for any RWH system, the basic calculation entails the formula:
Roof Area (square meters) x total annual rainfall (mm) x efficiency factor/runoff coefficient) = annual water supply in liters
2. To determine how much water a family consumes:
(Annual Water Supply)/ [Family size (# of people) x 365 (days/year)] = Liters per person per day
*generally consumption ranges from 50-300 Liters/person/day for drinking, cooking, bathing, flushing, laundry, and gardening
3. Components of a Rooftop System:
| i. Catchment (Rooftop) Materials: Cement, Corrugated Steel, Tile, Thatch The efficiency of the water catchment system is dependent on both its composition (i.e. steel vs. thatched) as well as the degree of inclination. Note that different materials can account for the variability in the runoff coefficient as well as the amount of bacterial growth, which may be higher on organic matter, as palm fronds. The selection of material is limited both by cost and feasibility; note while thatched roofs are cheapest, they are the poorest catchment surface. |
| ii. Conveyance (Pipes & Gutter) Types: plastic (PVC, etc.), Folded Steel Sheeting, Wood/Bamboo, other metal/ceramic These materials are dependent on only on cost but also on their longevity, sustainability, and ease of use. While PVC pipes may be relatively easy to use and cheap to buy, their production creates a large and negative environmental impact, particularly for individuals living around PVC facilities. Though other alternatives to PVC pipes exists (ex. concrete, steel, galvanized iron, clay, chlorine-free plastics as high-density polyethylene, and polyisobutylene), this area lacks research as a result of poor demand. |
| iii. First Flush Separation A First flush separation system may be as simplistic as a simple gutter pipe attached to a hinge. As the attached bucket fills with water (generally the first 5 liters are flushed), gravity causes the gutter pipe to tip, allowing the flow of water into a storage cistern. There also exists more complicated designs which essentially performs the same function.  |
| iv. Filtration see water purification |
| v. Storage -Materials: precast concrete, steel, plastered brick, brick, plastic -can be an underground chamber lined with cement, clay, mud, plastic, or brick; generally this scheme is less expensive but harder to maintain. Furthermore a pump is required to access water.  |
Some considerations for storage design and construction should including the following:
- safety; allowing ease of access to water without creating a drowning harzard to children or passer-bys
- designs must exclude vermins and disease carrying vectors (i.e insects, mosquitoes) as well as light which may facilitate the growth of algae and larva. Designs must also have adequate ventilation to prevent anaerobic decomposition of matter remaining in water.
- designs must provide structural strength to withstand wear and tear, and occasional large natural forces.
- designs must be made of non-toxic materials which does not influence the taste of water.
C. Collection liquid water from atmospheric water:
Note that the aforementioned rainwater harvesting systems rely rainfall, which with changing climate patterns may become unpredictable and erratic. Because of this, we should analyze systems which can extract water from non-conventional atmospheric sources.
Island Sky vs. Aqua Science Water Extraction System
Aqua Science has developed a water extraction machine that is able to collect water from the atmosphere. The machine works by pushing air through a liquid salt solution of lithium chloride, a hydroscopic compound which attracts water from its surroundings and naturally decontaminates it (excluding inorganic water contaminants). Because the compound used by the machine attracts water molecules and concentrates it, it allows water to be harvested from arid regions as well as humid regions. Their current atmospheric water extraction machines can provide approximately 350-1,200 gallons of water per day with a target price of approximately $0.25 per gallon depending on climate, temperature, and costs of setup and electricity. The benefits include:
- 2 Models: 20 foot or 40 foot emergency water station. The 20 foot station can provide approximately 600 gallons of water/day without using or producing toxic materials and by products. The 40 model can provide up to 1,200 gallons/day (depending on conditions) ands includes a reverse osmosis module that can provide up to an additional 8,000 gallons/day from an existing source (i.e. desalination of ocean water).
- Both models can provide “off-grid” water production using a featured power generator (7-day supply) or can be connected to an electrical grid
- Contain models can produce up to 1,200 gallons of water per day for 7 days without outside electrical source or refueling.
- Furthermore, the machine (comparable to a mobile home) can be affixed or portable in order to distribute water to isolated or rural areas.
Island Sky, an Austrailian based company, similarily devised a machine which also extracts water from the atmosphere. However, their employed a adiabatic distillation process which replicates the natural process where water vapor condenses into liquid water by continuously mimicking the “dew point” using vapor compression. Air is drawn through a specially designed filter that removes dust, purifying water vapors. As water condenses it is then collected in the water storage vessel and is purified with OZONE, an EPA and FDA approved purification system. Unlike like Aqua Science, the Skywater machines are small, personal, and are targeted to replace run-up-the-mill water coolers. Several advantages of Skywater are listed below.
· Skywater 14 is energy efficient and can make a gallon of water as low as $0.16 per gallon for the 110 volt model.
· It requires no plumbing or general assembly and runs on a standard 110 or 220 volt electricity
· Water output performance is up to 14 gallons per day in optimal conditions and 3 gallons per day at 40% relative humidity
· Electrical consumption is 2 kilowatt hour/gallon of water produced in humid conditions for the 110 volt and 220 volt model
However, disadvantages include:
- Requires electricity from a grid. In rural or isolated locations where electricity is not available the machine should be adapted to include usability via an electrical generator.
- Safety features include an LCD display which provides warning indicators when replacement parts reach expiration limit. The system will automatically shut off and display will indicate which parts need service or replacement. Complicated features as the LCD screen are not robust and should be adjusted to meet requirements specified by a local region. Furthermore, these safety features in part require technological training and literacy and need to be adapted for individual countries and regions to ensure language and cultural compatibility.
- Skywater is EXPENSIVE, costing approximately 1000 U.S. dollars per unit. Furthermore, because it is a smaller machine that is not intended for the mass collection of water, its output may not be sufficient to supply water for a family given no other water sources. Estimated water use in Bangalore is illustrated in Figure 5 below, demonstrating that on average a person consumes 135 liters per day. Though this range may vary between 50-300 liters, Skywater (under optimum conditions) is only able to produce 14 gallons per day translating to approximately 53 liters.
Both Skywater and the Aqua Science Module was intended to generate water fit for drinking, which essentially increases the cost of water produced given the extra cost of filtration and purification . From Figure 5, humans understandably use water for many other functions other than drinking and cooking. In conjunction with these water extraction systems, sustainable water practices may include the use of rainwater for gardening, laundry, and bathing which do not require water purified to drinking standards exclude the higher costs of purification. Although the use of Island Sky can reap enormous benefits for developed countries, where the population can afford to own individual units, it is economically unfeasible for developing countries at its current price given its water output. Conversely, Aqua Sciences, though given its high initial cost, is more adapted to the water needs of developing countries, like India, where a large and concentrated population require a large amount of their water from an artificial source (i.e. a water truck). In this sense, Aqua Science's machine, originally designed for diaster relief, can in part replace the use of water trucks in order to reduce the cost of water transportation.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Other Ideas:
| WatAir, created at the Technion-Israel Institute by graduate students, is an inverted pyramid array of panels that collects dew from the air and turns into freshwater. One 315 sq foot unit can extract a minimum of 48 liters of fresh water from the air each day. It’s vertical and diagonal design utilizes gravity to increase collection area. |  |
| A highly efficient wind turbine that can run a refrigeration system to cool air and condense moisture from it. Moisture in the air is cooled by a drop in pressure behind the turbine blades. The air then flows into a chamber containing refrigerated metal plates covered by a hydrophobic surface that causes water droplets to run off into a collection point. A 4 meter square device can extract an average of 7500 liters of water a day. However, the device requires a lot of energy. Because wind turbines are only about 30% efficient at best and the energy arriving at them is very diffused, the device must be sufficiently large enough to collect energy. |  |
Figure 4: Skywater 14 Water production chart, depending on the variability of temperature and humidity.
| Estimated Water Use for the City of Bangalore | Liters/person |
| Drinking | 3 |
| Cooking | 4 |
| Bathing | 20 |
| Flushing | 40 |
| Laundry | 25 |
| Washing Utensils | 20 |
| Gardening | 23 |
| Total | 135 |
 Figure 7: Skywater |
 Figure 6: Aqua Sciences 20-foot Water Container |
Our next focus is going to be on the Purification of Water
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Why is it important to purify water ?
Before discussing the ways to purify water, it is important to be aware of the present conditions of drinking water in third world countries. About 60% of the households in Patna, India, drink contaminated water. In the last two months, the Patna Water Board (PWB) collected 150 water samples from different parts of the city. After testing, about 45 samples were found unfit for human consumption. These were found containing bacterial contamination, including e-coli. In October, 2000, the arsenic hazard in Bangladesh villages resulted in the accidental poisoning of about 85 million out of its 125 million people. Arsenic contamination is a natural occurring accumulation of highly concentrated arsenic in deeper levels of groundwater. This accumulation of arsenic has increased substantially due to the use of tube wells for water supply in the Ganges Delta. A 2007 study found that over 137 million people in more than 70 countries are probably affected by arsenic poisoning of drinking water. The U.S. Water News published an article in 2003 about the leading cause of cancer in Lucknow, India - the cause is the impure water drunk by over 70% of Lucknow’s population. About 2,300 cancer patients visit King George's Medical College hospital in Lucknow, the state capital, every month. Eight years ago that figure was less than a 1,000.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------
Reasons behind Water Impurity
There are several background reasons to this issue. The biggest being the lack of action by the Government of India. On April 22nd, 2002, more than 2,000 irate protestors gathered at the Hindustan Coco Cola Company in Plachimada, Kerala. Coco Cola’s indiscriminate mining of groundwater [illegally] has mined up many wells and contaminated the remainder. The water was declared to be very hard, as the constant extraction of the water had increased the rate at which the water flows through the limestone or clay. What did the government do about it? Nothing. In fact, rather than attacking the Coco Cola Industry, the protestors were arrested and persecuted. In the absence of any law to regulate the extraction of groundwater, people or companies with resources and money can privatize aquifers just by virtue of owning a small piece of land. Reason Two, In India, a sacred lake is used for many functions such as praying, cleaning, defecating, drinking and cooking. The only purification technique employed is the boiling of water (which is not enough to eliminate all the contaminants). Pollution and industrialization that occurs due to the arising industries in India also add to the misery.
Figure Eight. Water Strike against Coco-Cola Company
Reason Three, the tubes carrying clean drinking water sits most of the time next to the sewage lines. One crack, one break, one monsoon season allows the two to mix and the drinking water becomes contaminated with feces. There are several diseases caused by this sort of contamination – the biggest being vibro cholera. Mosquito-borne diseases are also transmitted through the fecal matter. This explains the lack of eradication of diseases such as malaria. On July 2005, 14 people died over one weekend due to malaria (mainly passed by the contaminated drinking water). So there is no doubt that the situation is severe. However, each of the aforementioned issues can be solved by the implementation of a simple, cost-effective purification technology owned by a private company such as Water Health Technologies [whose mission is to implement the technology to meet the needs of rural villagers].
Figure Nine: Woman walking in the sewage mixed monsoon water
---------------------------------------------------------------------------------------------------------------------------------------------------------------------
Purification Technologies and UV Waterworks
There are many purification technologies that are already in use in many parts of the world. However, their success has not been great. Reverse osmosis ( using pressure to make water go from high concentration to low concentration, thereby separating impure solvents), desalination ( removing salt from sea water), water softening (removing hard metals from water), ultra filtration (using UV rays to filter water) have existed for almost 2 decades. The issue with current technologies is scalability and afford ability - what is needed is a SIMPLE, COST-EFFECTIVE purification technology that can be used by illiterates in rural villages, most of whom earn less than two dollars a day.
One such technology that meets the budget of a rural villager and is extremely simple to use is UV Waterworks (UVW), designed by Dr. Ashok Gadgil. This technology uses an ultraviolet light source suspended in air to inactivate a broad range of microorganisms. However, unlike many other ultra filtration technologies, UV Waterworks needs low maintenance and requires low energy. The instrument inactivates microorganisms by disrupting their DNA processes and so when the pathogens try to replicate, they die.
Figures Ten and Eleven. UV Waterworks designed by Dr.Ashok Gadgil.
The UVW uses only 60 watts solar cell (energy equivalent to one car battery to provide safe drinking water to approximately 2000 people. Gravity powers the flow of water into the UV chamber, deactivating 99.95% of contaminating bacteria and viruses. UVW is a size of a microwave and weighs only 15 pounds. This makes the technology scalable and implementing in any rural, remote area will be easy. The technology requires low maintenance and the unit aims to be completely failsafe. If there is any sort of malfunction, the entire system shuts down and the valve closes, allowing no water to enter the device. The next important question is quantity. Would such a small device be able to purify enough water to meet the demands of a village? Yes. UVW can disinfect water at the rate of four gallons/minute. Roughly 2880 gallons of water can be purified if the device is on for 12 hours each day. Villagers who have extremely low budget income can easily afford the water as UVW gives 1000 gallons for 5 cents. The officers of National Drinking Water Mission in India have determined that 20 cents per person per year is affordable for drinking water disinfection, UVW beats this price without sacrificing the quality of the water. The World Head Organization declares the water to surpass its standards of clean water. So there is no doubt that this technology makes heads turn in all directions, however implementation and acceptance by rural villagers plays a key role in the success of such a technology.
Worldwide, two hundred UVW units have been installed, mostly in Mexico and the Philippines. Approximately 200,000 people rely on UVW just within Mexico and Philippines. UV Waterworks was part of the first integrated community water system in Zihuatenejo, Mexico, located near Acapulco. This station alone provides water for 2000 people each day. In the Philippines, "Aqua Sure" water stations have been established in urban communities, where people can buy UVW treated water for a third of the cost of bottled water. Additionally, the Rotary Club has funded community UVW water centers in many Philippine public schools located in very poor areas of Manila. This technology is also being implemented in many other countries. In fact, the first field testing supported by the Department of Energy was performed in Durban, South Africa. In these tests, UVW was installed at a hospice for abandoned infants, the majority of whom were HIV-positive. Before the installation, approximately half of the children died from AIDS-related complications. Use of the UV Waterworks device significantly improved these children's chances of living with HIV.
Cons of UV Waterworks
After getting in touch with Dr. Ashok Gadgil, it was found that UVW works only on organic pathogens and not on metals. So UVW will no way help in taking out arsenic from the water. This is a big con. Next, the one time payment of $300 for one UVW unit might be too expensive for many villages. If some sort of grant or loan was giving to these villagers, with time they will be able to pay for the unit.
Pros of UV Waterworks
Women, who are usually the water carriers and purifiers, have more time to do other things. Longer lifespan that is made possible by UVW can yield more lifetime savings. People from the village can be trained to maintain the machine (the parts are easy to find in any hardware store) and to run it. Some villagers can market the instrument. UVW can be more than just a clean water provider, it can be the source of revenue for a village! A small price can be charged for the usage of the instrument. Small jobs for maintenance, regulation, distribution and marketing can arise and help the economy in the long run.
Implementation Issues
One of the other biggest barriers faced by UV Waterworks in its implementation in India is its culture. In many parts of India, women sings songs, while fetching the water or while boiling it. The 2 mile walk to get water and the boiling processes has become part of the culture and the fear of technology, itself, serves as a barrier. While boiling the water, women sing songs If the people in the villages that have used UVW market it, the trust of the rural people will be earned and the technology can be implemented.
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Research Links:
ttp://www.gizmag.com/go/4418/globalwater.org
http://www.newsroom.ucr.edu/cgi-bin/display.cgi?id=1219
http://wiki.edc-cu.org/blogs/index.php/videos/2007/12/14/p747
http://www.h2ro.com/_Solutio2.htm
http://dst.gov.in/scientific-programme/t-d-joint-techsys.htm
http://www.news.dow.com/dow_news/feature/2007/07_02_07/index.htm
WaterHealth
http://web.mit.edu/invent/www/ima/gadgil_diag3.html http://www.islandsky.com/ http://www.allatoms.com/WaterBottlePage.htm http://www.sciencedaily.com/releases/2007/06/070604222124.htm http://usmilitary.about.com/cs/armyweapons/a/arwater.htm http://www.wired.com/science/discoveries/news/2006/10/71898 http://www.aquasciences.com/products.html http://americanobserver.net/2006/10/05/florida-company-unveils-disaster-relief-tool-that-plucks-drinking-water-from-dry-air/ http://www.maxwaterdesal.com/projectedoutputs.htm http://www.earth-policy.org/Books/Seg/PB2ch03_ss2.htm http://news.bbc.co.uk/1/hi/sci/tech/3754520.stm http://www.rwh.in/ http://www.indiawaterportal.org/tt/rwh/ http://www.indiatogether.org/2005/mar/env-barrel.htm http://www.indiawaterportal.org/tt/rwh/courses/DebbieRTRWHPresentation.pdf http://www.patp3.webbler.co.uk/doc.php?id=671§ion=14 http://www.teachersdomain.org/resources/ess05/sci/ess/watcyc/rainfall/index.html http://www.abc.net.au/science/news/stories/2007/1860729.htm
http://www.unep.org/dewa/assessments/ecosystems/water/vitalwater/index.htm http://ga.water.usgs.gov/edu/earthwherewater.html http://www.who.int/water_sanitation_health/publications/facts2004/en/index.html
maLiNi17 |
Latest page update: made by maLiNi17
, Feb 20 2008, 5:31 PM EST
(about this update
About This Update
Edited by maLiNi17
13 words added 24 words deleted view changes - complete history) |
|
Keyword tags:
None
More Info: links to this page
|
There are no threads for this page.
Be the first to start a new thread.
