FiltiVest
Brittany Chiu, Katelyn Duncan, Rudri Pathak
The Pennsylvania State University, College of Engineering, University Park, PA 16802
Abstract
In many areas in India there is a lack of access to clean drinking water. Access to water is not the
problem; the problem is that the water is contaminated with pathogens, chemicals, and minerals that
cause disease and sickness to the consumers. Due to the water source being fairly far away, the design
for a water filtration system needs to utilize storage, transportation, and purification all in one. The design
called FiltiVest includes a vest that can be placed over top the shoulders with the water filtration device on
bothsides, front and back. The dirty water can be poured into the top where it will then filter down towards
the bottom. The filtration system will use a process known as Solar Disinfection (SODIS) that employs the
UV rays from the sun to kill pathogens and bacteria living in the water. The exact material of the filtration
system is a graphene polymer sheet. As the purified water seeps down the vest it can be stored at the
bottom. Attached to the bottom is a spigot where the water can be poured out. The cost will be around
$25 and will weigh approximately 2 pounds without water and 10 pounds filled with water.
Introduction
In villages where the conditions are arid and adverse, civilians are faced with the hardships of obtaining
water that is essentially and suitable for living. This holds true for those living in the rural communities in
India. Unfortunately, these villagers are forced to drink and use contaminated and infected water for
domestic purposes. Ground water in some locations in Jharkhand, West Bengal, Himachal Pradesh and
Delhi have reported levels of DDT, aldrin, dieldrin and heptachlor that are in excess of prescribed
standards, all of which are hazardous to the water the natives drink. In fact, 37.7 million Indians are
affected by water borne diseases annually. The water borne diseases in India are bacteria (E Coli,
Shigella, V cholera), viruses (Hepatitis A, Polio Virus, Rota Virus) and parasites (E histolytica, Giardia,
Hook worm)[5]. 1.5 million children die of diarrhea caused by drinking water. 60 million people are at risk
due to excess fluoride in the water and 10 million at risk of digesting amounts of arsenic in water [2].
There are also many other elements found in the water that cause a range of sickness and diseases.
Women and girls collecting water are also susceptible to leptospirosis, a bacterial infection from water
that is tainted by animal urine [4]. All these illnesses and diseases can be prevented if there is an access
to clean drinking water.
The water supply comes from either surface water or groundwater. The Himalayan River has a constant
flow of water year round. It has the largest source of fresh water and heavy rainfall during the monsoon
season. The coastal rivers (Bramhaputa and Krishna) have small catchment areas for water. The
peninsula river (Malanadi, Godavari, Krishna, and Kavar) has good flow of water during the monsoon
season. The Mahandi and Godavari rivers inland sometimes dry out as the water drains to other bodies of
water. The monsoon season is between June and September and about 75% of the total annual
precipitation comes from these months. However, the government is unable to store it properly for the dry
season. Overall, groundwater is the major source of water. The average groundwater recharge rate in
India’s run basin is 260m^3/year. There is 4000 billion cubic meters of rainfall a year. Unfortunately, only
48% ends up in rivers and 15% is utilized. Climate change has been depleting the supply of water and will
even more so if the glaciers dry up [2].
Organic pollution measured in terms of bio-chemical oxygen demand (BOD) and coliform count gives an
indication of the extent of water quality degradation in different parts of the country. It was observed that
nearly 66% of the samples had BOD values less than acceptable limits while 44% of the samples
indicated the presence of coliform while according to the BIS there should be no coliform in drinking water
samples. Overexploitation is one of the problems that results in pollution in the water. An example of this
is by the right bank of the Ganges river where there is now high amounts of arsenic and fluoride. In a
survey by the Central Control Board of Pollution they identified 22 sites in 16 states of India as critical for
groundwater pollution. Organic pollution is one of these problematic types of pollution in the water. There
is also excess iron, nitrates, and brackishness, which, directly increases the salinity of the water [4].
There needs to be an approach that seeks the participation of users through interventions engaging the
communities with various government schemes and policies. Citizens should be made aware of the
demand for clean drinking water as a right. Such an integrated approach would incorporate collaborative
efforts of various sectors involving the government, civil society, and the people. There needs to be a
support of awareness and accountability. In addition there is a need for testing and remedial actions,
water quality standards and provisions of water under the Food Law Bill, school water supply programs,
role of environmental sanitation and hygiene, water harvesting, maintenance, waste water treatments,
and community based water quality [4]. On a small scale solution, ways to treat the water for families
alone will also slowly help more and more groups of people start to have access to clean drinking water.
Design Considerations
In order to fulfill the needs of the citizens living in arid conditions, and in areas where water is not easily
accessible, a water filtration system has to be created in order to provide clean water for families living in
countries that are not as industrialized, such as India.
Since the focus is on places in India, a consideration that has become a factor is the distance between a
community and the source of water. The female citizens would be the ones who mainly have to make
multiple, fairly long trips, to collect water, which is many times, contaminated. A new device would be the
most efficient if the weight could be evenly distributed so that more water can be collected, resulting in
fewer long trips to obtain water. The device should not be bulky, so the material should be flexible and no
larger than the size of the human torso. Since there are pathogens and contaminants located in the water
directly from the water source, the new design would have to filter out harmful particles leaving only
drinkable water.
Typically, the water sources for many families in the isolated villages of India are approximately a 30 to 45
minute walk from the village, each family only retrieving water for their own homes [5]. Table 1 shows the
distribution of the population of a village in India on how much time it takes to reach their water source.
This poses a problem for families as they need to travel, sometimes multiple times a day, to collect water
that is usually contaminated. A contributing factor to this problem is that only a few citizens are aware of
groundwater storage and rainwater harvesting. One of the goals of the design product is to minimize the
negative consequences associated with having to travel to collect drinking water
Table 1. Shows the distribution of the population in how much time it takes to travel to water source [5].
Time to travel to water source
% of population
< 30 min
35%
30-45 min
35%
45 - 60 min
22%
> 60 min
7%
.
In today’s age, local communities in India clean water by boiling and methods of irrigation. Other
processes of water filtration include cloth filtration, Cascade Step-Drop Aeration System, and the slow
sand filter [1]. Though these methods work, boiling would only remove most but not all of the live
pathogens, and irrigation requires too much time and energy to create and maintain. Therefore, the new
design should be easy to maintain and cost efficient. Furthermore, the design of the device should be
simple and contain the fewest number of parts as possible. The simplicity of the device will help ease the
problems that come with a language barrier.
Research shows that UV and thermal radiation are good methods to remove living biological
contaminants from water sources [7]. Due to the fact that India is located in an area where sunlight is
available in excess, these methods are favorable in efficiency. The places located in the community are
fairly clean, but if the device needs to be placed outside when utilizing sunlight, there should be a way to
keep the device fully exposed while not obstructing the path of civilians. Children should be able to use
this device as well.
Currently, the government in India is somewhat involved with this issue of water conservation. They have
begun propagating efficient water use and creating awareness on water conservation. In some city areas,
the government has also implemented a policy on mandatory rainwater harvesting systems. When asked,
many villagers were ready to use new technologies if the government provided subsidies for them [2].
Due to this, cost is a prominent design consideration.
Finally, when storing the water, the device should be self containing, meaning that it can hold the water
until it is consumed. This would be most efficient design because no extra steps would have to be taken
once the water is originally placed in the unit.
Proposed Solution
In the design of the FiltiVest (Figure 1), water could be collected and worn as a vest which distributes the
weight of the water over the shoulders. As the individual collecting water is walking, a filtration system
towards the bottom of the vest would be filtering out the contaminants, leaving clean water at the bottom
of the vest.
In this design, a process known as Solar Disinfection (SODIS) is
utilized since the sunny climate is prevalent. Long hours of sunlight
would provide enough UV light to remove a significant amount of
the bacteria and pathogens. Since the temperature in India rises to
above 50 degrees Celsius and there are many areas of complete
direct sunlight, SODIS, in addition to the filtration system, will clean
the contaminated water effectively. However, the device must be
kept outside and be exposed to the total amount of direct sunlight to
function the most effectively [7].
Focusing on the filtration system, the FiltiVest, when filled up, would
still have approximately 1.5 inches of empty space on the bottom on
the device. Roofed above this empty space would be flexible sheets
of filter material made of grapheme. A cartridge would become
saturated with water and would prevent larger contaminants from
the clean portion of the filtration device. After saturation, only water
Figure 1. Design of the FiltiVest
molecules and small particles would move across it. Disposable
and replaceable filters require some effort in the exchanging of filter
sheets, but the benefit is the lower cost of filters. The thin sheets would then obstruct the smaller particles
from entering the drinking water since only water can pass through the small pores. Clean water can be
emptied through a spout located on the bottom corner of the device. Once the clean water portion of the
device is near empty, the force of gravity and osmosis would allow more dirty water to be filtered and
dripped into the clean water area. The process would continue until the content of the water bags are
depleted. The actual compartment used for storing water can be from any cost efficient materials such as
recycled plastics. This would lower production costs by a significant amount.
The filtration material being used is a grapheme polymer sheet (Figure 2). The sheets will be held in a
cartridge where the filtration sheets can be replaced. One gram of the polymer is $250 but the weight of a
single sheet is so insignificant that the price will be low. Graphene is also very durable and therefore the
sheets in the filtration system would not have to be changed very often, if at all, during its use. Overall, it
is estimated that about 2 liters of water will be able to
be decontaminated on each side of the vest. This would
result in the vest weighing about 2 pounds without
water, and 10 pounds with water. This is a reasonable
amount of weight considering that at the end of the
filtration process the consumer is rewarded with purified
drinking water. The average person is advised to
consume 1.893 liters of water per day. With the Filtivest,
only one trip to the water source is need to provide
clean drinking water for a day for two villagers.
The materials used in the fabrication of the storage unit
can originate from recycled materials such as the
plastic bags that once used for the transportation of
wheat and grains to the villages. This would cut down in
production cost since the only components that have to
be completely manufactured are the graphene sheet
filter cartridges.
Figure 2. Graphene filter molecular illustration
(Source: http://www.popsci.com)
The FiltiVest addresses the issues dealing with the purification of the water consumed and the
complications that are tied into physically transporting the water. This new design answers the questions
regarding language barriers because of its simplicity in design. The cost of materials should not exceed
$20 to $25 in production costs per unit. Each dollar spent would be used efficiently because the cost of
one gram of graphene can be utilized in the manufacture of a large number of FiltiVest units.
Conclusions
A double sided vest will be utilized in order to both collect and decontaminate drinking water in the Indian
subcontinent and in similar arid-rural settings. The material of the vest will be made with strong
transparent recycled plastics or similar materials. There will be a filtration system inside the bag on both
sides of the vest. The consumer can take the vest to the water source and fill the bag up with the
contaminated drinking water. Both sides of the vest will be utilized for collecting drinking water, holding up
to 2 liters on both sides of the vest. The filter will be made from graphene and will remove any debris and
dirt from the collected water while the transparent bag will allow for the Solar Disinfection process to take
place. Graphene is a highly durable polymer that has been shown to only allow water molecules to pass
through it. Using this new material as the filter will ensure proper filtration of dirt and debris The clean
and disinfected water will collect at the bottom of both sides of the vest and can be removed through a
spigot for drinking purposes. The FiltiVest is a portable and manageable water filtration system that can
easily be refilled and controlled. For further studies and to aid in creation of a superior design, surveys
can be conducted in the villages of India to determine specific needs of the village including average
water consumption and distance needed to travel to collect water. Also, by studying the human body and
weight distribution, the design of the vest can be perfected to ensure comfort, durability, and mobility.
Another investigation that can be conducted is to test the water before and after the purification process
to see if the levels of bacteria, pathogens, and chemicals in the water decreased or were filtered out
completely.
Acknowledgements
We would like to thank Dr. Margaret Slattery for providing materials and work space for the construction
of the prototype.
References
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