We often notice dew drops on leaves, grass and some sloping surfaces in the morning hours. These dew drops can actually be a source of drinking water.
A group of Indian scientists, working with experts from France, has developed technology for harvesting dew or atmospheric moisture for drinking water purposes and shown that it can be a cost-effective option in water-stressed regions like Kutch in Gujarat.
India’s first potable water production plant designed to harvest atmospheric moisture and process it into drinking water has been set up at Kothara village in the Kutch region. It has a capacity to process an average 500 litres of water daily.
The dew-harvesting technology involves harvesting dew using specially designed condenser panels, storing raw water and putting it through afiltration process. When conditions for dew formation are right--clear sky and humid coastal breeze--the panel surfaces cool to the dewpoint temperature causing condensation. Condensing water flows down the sloping sides by gravity into a central channel.
Condensation can occur over several hours of the night often extending to early mornings. The collected water is then put through a multistage filtration and purification process. The filtered and purified dew water has been found to meet the WHO standards.
“The condensation panels mimic the condensing behaviour similar to those of plant leaves and blades of grass,” explained Anil K. Roy, a member of the research team and an associate professor of physics at the Dhirubhai Ambani Institute of Information and Communication Technology (DAIICT), Gandhinagar.
The condenser field, which looks like a solar plant, is made of 30 rows of condenser panels, each 18-metre long and 1-metre wide. These panels are sandwiched with 25-mm thick styrene foam board in the middle and wrapped around with a special plastic film. The panels are mounted on angle iron frames at a height of 1.5 metre from theground.
“Collecting rainwater is simple, but harvesting dew is very challenging,” Prof. Roy told India Science Wire in an interview. “The dew condenser, designed, developed and field-tried by us, is novel. Condensers are planar panels made of high emissivity plastic film insulated underneath. They get cooled by re-radiation at night and can harvest 15 mm of dew water in the season. While condensers are specifically engineered to condense dew, rain can be routinely harvested using the same surface.”
The project was conceived by Prof. Girija Sharan while he was at the Indian Institute of Management, Ahmedabad. Later he shifted to DAIICT and subsequently passed away. The results of the study have been published in the Journal of Cleaner Production. French researchers participated in designing of the plant and conducting simulation studies.
The aim of the project is to demonstrate that atmospheric moisture can be harvested and processed into safe drinking water comparable in quality and price to RO (reverse osmosis) processed water. RO units are being widely used in the village in the absence of any durable source of drinking water, though it results in wastage of water.
“The expected yield of filtered, treated potable water from the plant is 150,000 litres a year.
The cost to produce one litre, accounting for investment and running costs is expected to be Rs 0.5 for one litre of bottled water,” said Daniel Beysens from Pierre and Marie Curie University. “We are discussing with other countries to build similar plants there,” he added.
The Kutch region gets around 300 mm of rain over 15 to 20 days during the monsoon season, while dew occurs from October to May with 100 to 115 dew-nights and 20-25 mm of dew water over the season. A suitably designed dew-cum-rainwater harvesting plant can potentially harvest 320-325 mm of rainwater and atmospheric moisture during a year. Ability to harvest both rain and dew from the same catchment improves theeconomic viability of such systems.
Most of the 800 villages in Kutch experience shortage of safe potable water for residents and livestock. Out of them, about 150 villages have been categorised as "no source" villages and have to depend on water transported from long distances daily.
The research team included the late Girija Sharan and Anil Kumar Roy from DAIICT; Laurent Royon from International Organisation for Dew Utilisation (OPUR) France; Anne Mongruel and Daniel Beysens from Pierre and Marie Curie University. The research was funded by the Department of Science and Technology (DST). (India Science Wire)
FAQs
The dew-harvesting technology involves harvesting dew using specially designed condenser panels, storing raw water and putting it through a filtration process. When conditions for dew formation are right--clear sky and humid coastal breeze--the panel surfaces cool to the dewpoint temperature causing condensation.
Can dew be used as a water source? ›
However, it can be a source of fresh and pure water for plants, animals and humans. Dew water is indeed drunk by many small animals and insects, especially in arid and semi-arid regions (but not only, there are many examples of animals, such as cats and dogs, drinking dew water in our countries).
What is the source of drinking water in India? ›
What are the sources of drinking water in India? Drinking water in India is mostly derived from groundwater that is pumped via handpumps from borewells, tubewells, dugwells, and surface water sources like rivers, streams, ponds and lakes.
Is morning dew safe to drink? ›
In this case, you can collect morning dew and drink it. This refreshes the body and allows you to prepare yourself for all the activities of the day and keep you energetic. Relief from pimples: Morning dew has high oxygen content, which makes it suitable for skin care.
Is dew water clean? ›
Atmospheric moisture water is clean and does not pollute the environment. Dew yields estimated from meteo data and Computational Fluid Dynamics.
What is dew in the Bible? ›
Associated with God's favor and love. Dew is a symbol of resurrection (Isaiah 26:19). Just as the earth brings forth it's dew, so also it shall bring forth the dead to new life. Dew is a symbol of the redeemed and resurrected people of God. Dew is associated with manna and thus food (Exodus 16:13-21).
What is India's main water source? ›
Ans. Groundwater is the main source of water in India. Ans. Surface water, subterranean river flow, groundwater, and frozen water are all-natural freshwater sources.
Which is the cleanest water source in India? ›
The Umngot River in Meghalaya is considered the cleanest river in India.
What is India's chief source of water? ›
Surface and groundwater storage
India also relies excessively on groundwater resources, which accounts for over 50 percent of the irrigated area with 20 million tube wells installed. India has built nearly 5,000 major or medium dams, barrages, etc. to store the river waters and enhance groundwater recharging.
Is Coca-Cola healthier than Mountain Dew? ›
Cola is 6 times more acidic than Mountain Dew. However, Mountain Dew contains a different type of acid that is more difficult for the saliva in your mouth to buffer so it makes your mouth acidic for a longer time and is more damaging to your teeth. Both Mountain Dew and the Cola were harmful to the teeth.
Drink it in moderation. Limit yourself to two or fewer servings each week — it shouldn't be a daily habit. Drink soda in one sitting. Sipping it over a prolonged period doesn't give your mouth time to recover.
What is the purpose of dew? ›
As dew evaporates, it cools the plant down in much the same way that evaporating sweat cools your body on a hot day. This reduces heat stress in very hot environments. Some species, especially desert plants, can actually absorb water directly through their leaves. For these species, dew is a direct source of hydration.
How to collect morning dew for drinking? ›
Collect dew with a towel
This is perfect if you are in an area where there is a heavy early morning dew. Simply drag a clean towel over a dew-covered area then wring it out over a bowl. You may not collect a lot of water this way but you can often get enough to keep you going until you find a better water supply.
What is the spiritual meaning of dew water? ›
The miraculously refreshing and reviving effect of dew upon the plants in the Holy Land prompted Isaiah to use it as a figure of resurrection (see Isaiah 26:19) and Hosea to use it as a figure of repentance (see Hosea 14:4–5).
Is morning dew just water? ›
Dew is the moisture that forms as a result of condensation. Condensation is the process a material undergoes as it changes from a gas to a liquid. Dew is the result of water changing from a vapor to a liquid. Dew forms as temperatures drop and objects cool down.
Does dew count as watering? ›
During cool nights, water from the air precipitates on plant leaves. Dew is not only aesthetic but is considered an important source of moisture and water for plant life.
Can plants get water from dew? ›
Only plants which are shallow rooted could make use of dew because the moisture penetrates only a thin layer ofsoil and evapor- ates quickly when the sun begins to warm the surface. Pineapple is an example of a plant whose trough-shaped leaves allow dew to run down to the plant base.
Is dew the same as water? ›
Dew is the result of water changing from a vapor to a liquid. Dew forms as temperatures drop and objects cool down. If the object becomes cool enough, the air around the object will also cool. Colder air is less able to hold water vapor than warm air.
Is dew water distilled water? ›
Dew is in essence distilled water and thus should not be, a priori, contaminated by heavy metals and dangerous bacteria, unless dew can absorb and dissolve the atmospheric gases around and the aerosols captured by the substrate. The chemical and bacteriological properties of dew are not well known.
