Product Need Identification: The Need of Solar Based Water Purification Systems

By

Nirupa Jain

(Research Scholar doing M. Tech. in Manda Institute of Technology, Bikaner)

And

Krishan Kumar

(Research Supervisor, Manda Institute of Technology, Bikaner)

And

Dr. Anshumala Sharma

(Research co-supervisor, Manda Institute of Technology, Bikaner)

(The writers are thankful to Mrs. Suman Choudhary of Manda Institute of Technology for her inputs)

Abstract

The society is facing the problem with regard to pure water. The researchers look at the present crisis and identify different methods for purification of water and suggest solar based water purification system to meet the challenges. This will help in meeting the problem. Since this technology will be based on renewable source of energy, so this will not create any problem with regard to shortage of energy also. The researchers therefore conclude that this should be promoted.

Keywords:

Solar, product, SDG, water

Introduction to the present day water crisis

Society needs products to meet its needs. Products should be designed and developed to enable the society to lead a better life and to meet the challenges of the society. There have been many instances where a product is popularized to meet the challenges of the society. Society is in a state of evolution. Those products, which were required earlier, may not be required today. While there may be requirements of new products today due to the challenges of the present times. Thus it is pertinent to remember that the society is not a fixed and static entity. It is constantly evolving and therefore there is a need to study and identify the products that shod meet the needs of the society in the future. There is a need to study the society of the present time and identify the products for the future. The focus of the management of the society, nations and institutions should be on development of new products and services to meet the challenges of the future. This will help the society in its transition and will enable the society in its development.

The sources of water are limited. Fresh water sources are now depleting due to many reasons. Climate change, rising pollution and rising human encroachment have put the limited fresh water sources in short supplies. The population in cities is rising and it is now becoming a challenge as to how to meet the requirements of pure water for the rising population. There is a need to look at this problem from a fresh perspective. We will require new products to meet with this challenge.

Recently the city of Cape Town in South Africa suffered severe shortage of water and therefore it had to immediately start three water desalination plants to meet the water needs. This has put the attention of the world to the growing crisis with regard to water scarcity. Now the entire world has started giving it an important priority. The rising urban population and the reducing level of ground water are creating challenges for the mankind about how to meet the needs of water in the future. There is a need of new products to meet the growing challenges with regard to pure water.

With the rise of the global warning, industrializing, water and land pollution, the impurities in the water has been increasing day by day. The researchers and scientist have been working on various methods for the purification. The research has been done on the best way such that the water may get purified without harming further, in the economic and eco friendly way. Various machines have been created, but the perfect solution has been still lacking. Some machines may give the purest form but may not satisfy the economic and the eco friendly need, on the other hand some have been economic but they lack eco friendly and the purification factors, and so on.

The raw water impurities and its harm over the living being has been center of the problem. The drinking water from the purification of raw water can be obtained from various methods. The equipment with the help of combining different principles and methods brings the best relevant water form for drinking purpose.

Raw Water

The water obtained from the natural sources. The raw water has been not as pure for the intake purpose, but the impurities have been not as equivalent to the waste water. The raw water sources include rainwater, groundwater, lakes, rivers, etc. The raw water can be useful in various purposes without being treated. As we know that the ocean water shares the largest ratio, alone. But the raw water cannot be included in the category. According to the global report, the raw water including the drinkable water includes only 4.75% of total water present on the earth.

Figure 1: Distribution of Water

The raw water has been used by human in various activities. The activities’ consuming it includes farming, constructing buildings, man-made lakes, washing clothes, flushing toilets etc. there has been a ratio of useful part from the raw water as well. As shown in the figure, only 0.3% has been totally useful.

Figure 2: Useful proportion of Water

The raw water varies from the places. The raw water depends on the climate, the pollution and various aspects. The rain water has been the purest raw water, when the rain water gets converted into the ground water, the impurities also increases. The impurities present on the ground get included in raw water. The ground water flows and further comes in the form of river water or forms lake, as the water flows, the impurities also gets higher. The impurities present in raw water generally vary as shown in the table:

Table 1- Raw water impurities range.

Harmful effects of Raw Water

• The impurities in raw water have been above the level of acceptable drinking water. The intake of such water may cause harm to the living being. The use of such water may also leads to harm. Some of the harmful effects have been discussed below.
• Intake of impure water may cause biological hazards on the living being. It can infect harmful diseases like waterborne diseases, asellus, Cyclops, etc
• It may cause a direct risk to health causing choking, etc. it may contains element infections such as pathogens etc.
• The raw water may contain certain amount of radium (man-made; neurotoxin pollution).

Basic impurities in raw water

Raw water may contain a lot of impurities. The drinkable water need not to be the purest, but the drinkable water must not contain impurities more than 300 tds (milligram per liter), whereas, the impurities in raw water lies between 500-30,000 tds. To use the most appropriate purification method, we need to study the basic impurities of raw water. The most common impurities in any form raw water include: ions (chloride, sodium, sulfate, magnesium, bicarbonate, bromide, boron, fluoride, and nitrate), bacterial impurities (infections), etc.

There have been various methods for purifying the impurities from the water. Most accurate and commonly used methods have been as follow:

• Boiling
• Charcoal filter or carbon filter
• Reverse osmosis
• Electric dialysis
• Ion exchange
• Distillation
• Demineralization

The purification of water has been done by evaporation and condensation method. The water has been a volatile substance, so when the energy from the solar rays in the form of heat, increases the temp of water, it evaporates, and as it has been packed in a closed system, it condensates on the ways, within the closed system. The water droplets which condensates on the wall will start to flow downwards due to the gravitational pull, and hence the water has been again stored. But the storage of the condensed water differs from that of evaporating. The evaporating water represents the impure water. The water purifies due to its volatility. The impurities in the water have been generally non volatile, so the condensed water will lack them. Due to rise in temperature, the bacterial organisms will not survive and hence this works as disinfectant. Although the process has been vivid for the purification from non volatile impurities and the harmful infections, but it lacks the purification from the volatile impurities, for e.g. chlorine, etc.

Solar distillation for purification of water

As discussed above, the solar distillation works on the principle of the evaporating and condensing. The working of the solar distillation has been based on the ‘volatile’ nature of the water. Steps regarding the process have been as follow:

1. The heat generated from the solar rays raise the temperature of the system.
2. The rise in the temperature causes the volatility of the water, forming vapors.
3. The vapors colloid with the walls of the system and reforms the liquid stage.
4. The vapors form droplets over the wall surface.
5. The droplets, due to the gravitational pull slides the wall surface.
6. The storage of these condensed water droplets has been different from where it evaporates.
7. Hence the purified water id obtained.
8. Requirement of solar distillation
9. There have been several dependencies of the solar distillation, on which the output depends. The requirement fulfilled can give a better output.
10. Material of the equipment
11. The material should have higher heat absorbance capacity.
12. The material should be stable at higher temperature.
13. The material should have higher strength so as to resist the inner pressure rise due to increase in vapors and entropy.
14. The resistance towards the reformation at higher temperature.
15. The material should be resistive towards the reactivity with water vapor and other volatile components.

Conclusion:

While solar based water purification system is good for the environment, it also helps in solving the present crisis of shortage of water. We are also facing shortage of energy. Therefore this product can help us in meeting the crisis with regard to shortage of energy also. Solar based power is renewable energy and therefore this can be a very useful product in the future.

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