Solar will take care of it

By Magazine Team Last updated Nov 12, 2022 688 0

Contents

1 Solar water disinfection

2 What is the procedure for solar water disinfection?

3 Advantages and limitations

4 Solar water disinfection limitations or drawbacks

5 References

Solar water disinfection

Solar water disinfection(SODIS) has been established for over 30 years. SODIS means solar disinfection, which is the process of using sunlight to kill bacteria in biologically polluted water.

The tainted water is then placed in clear containers and exposed to direct sunshine for at least 6–8 hours depending on the amount of sunshine and the pathogens’ susceptibility.

The bacteria that may ordinarily cause waterborne infections are inactivated and unable to cause illness after sun exposure.

Solar disinfection is often employed in low-income rural regions where no other method of distributed water treatment, such as chlorination, boiling, or filtering, is available.

Its germicidal impact is dependent on a combination of solar light thermal heating and UV radiation.

It is successful in removing microbiological pathogens and reducing morbidity, including cholera, on several occasions.

SODIS has been shown in the laboratory to inactivate the viruses, bacteria and protozoa that cause diarrhea while Field evidence has shown revealed decreases in viruses, bacteria,and protozoa in water treated with SODIS in underdeveloped nations.

SODIS has been shown to reduce diarrheal illness incidence by 9-86 percent in four randomized controlled studies.

Solar water disinfection is a simple, safe, cost-efficient, and effective way of cleaning polluted water.

To cleanse or improve the quality of drinking water, the approach simply includes the use of sunlight and plastic PET bottles.

What is the procedure for solar water disinfection?

The SODIS method involves filling polluted water into PET bottles or glass bottles (made of heat-conducting material and ideally painted black) and exposing them to direct sunlight for varying amounts of time, generally not less than 6 hours. The Sun’s light is a powerful source of energy.

Every second, around 1360 joules of solar energy fall upon each square meter of the Earth’s upper atmosphere.

The sun’s UV radiation elevates the water temperature during exposure, assisting in the inactivation/killing of diarrhea-causing microorganisms in the water.

Solar disinfection affects numerous important processes within the cells, according to careful microbiological study.

Cells stop manufacturing adenosine triphosphate (ATP), an essential molecule responsible for making energy available for most cellular operations, shortly after sun exposure begins.

This is rapidly followed by a decrease in glucose absorption, and the cell membrane gradually deteriorates to the point where the contents seep out into the environment, resulting in cell death.

Advantages and limitations

SODIS is a feasible water treatment system that improves the microbiological quality of drinking and cooking water.

The procedure is simple to implement in tiny towns throughout the world that lack a centralized water treatment plant or other treatment or disinfection options like filtration or chlorination.

This decentralized water treatment technology may be implemented at the household level under the responsibility of the individual user.

Because it depends on locally accessible materials, plastic bottles, and sunshine, the approach is cost-effective and has low investment.
SODIS has a lot of advantages as it decreases viruses, bacteria, and protozoa in water; reduces diarrheal sickness in users; has Acceptability among users due to its ease of use and after receiving the plastic bottles, the user pays nothing.

Solar water disinfection limitations or drawbacks

1-SODIS does not influence the chemical purity of the water.

2- This method of water treatment is ineffective for treating huge quantities of water.

3- It makes no difference in terms of boosting the water supply or relieving water scarcity.

4- The approach requires generally clean water, with a turbidity of less than 30 NTU.

5- Because of the restricted volume of water that can be treated at one time and the time it takes to treat water.

6- The enormous quantity of undamaged, clean, and acceptable plastic bottles that are required.

SODIS is most suited to locations where bottles are readily available, as well as community incentives and instructions on how to use SODIS effectively and regularly for purifying home drinking water.

The approach is reliant on favorable climatic and weather conditions, particularly in areas with abundant solar radiation.

This water purification procedure does not work well on days when it rains continuously or when it is foggy.

The location’s geographic latitude, The location’s elevation, Seasonal Exposure Time, time of day, Clouds’ Presence or absence, Temperature Volume of the water-filled container or vessel, Material of the water-holding bottle or vessel, turbidity of the water and Color of water are the main factors that influence the efficiency and safety of SODIS-treated water.