In today’s world about 780 million people, 11% of the world’s population, lack any type of access to clean water. This is widespread mostly through arid and semi-arid regions of the world due to low precipitation rates and scarce availability of natural water sources. Furthermore, water pollution also creates a severe problem with an estimated 3.4 million people dying each year from water related diseases. The combination of the two dilemmas has inspired the development of various techniques and technologies that can extract clean water from places that in the past seemed impossible. Such a technique is humidity harvesting. This technique has great potential in humid regions such as the MENA region, where humidity can reach upwards of 80% humidity (harvesting can only occur if humidity is over 69%).
Humidity harvesting is a very simple concept. It relies on the natural process of condensation to be able to extract water (in the form of water vapor) from the air and create fresh drinkable water. What is particularly interesting about humidity harvesting is that unlike desalination and wastewater treatment plants it can be inexpensive and easy to construct. However, like wastewater treatment and desalination it can also be quite expensive if it is to be used to maintain large communities.
Different techniques and technologies
Its ease of construction and low cost has led people to create different ways of harvesting humidity from the air (which rely on condensation). Three inventions whose use has been increasing are Skywell, Warka Towers, and Airdrop Irrigation. All three technologies do not require large amounts of income or advanced technologies to complete, and are designed to help remote communities, with little or no income, get access to clean water.
1. Skywell: This system uses the simple process of condensation on a cold flat surface to produce clean water. A large corrugated sail with hydrophobic (does not absorb water molecules) coating is used to condense and collect humidity from the air. The water is then directed into a reservoir where it is filtered so it can be used immediately or stored for periods of drought. Despite its simplicity this system will be able to produce up to 110 liters per day, supplying 60 individuals with their needed daily supply of clean water as long as the system is functioning. This will have significant effects on community and social development within poor and water scarce countries.
2. Warka Tower: This is an inexpensive 30 feet tall vase-shaped structure that is very easily assembled. It consists of an outer casing comprised of lightweight elastic wooden stalks, known as juncus, and a mesh net made of nylon or polypropylene hanging on the inside collecting droplets of dew that form along its surface. The droplets then run down the net and into a container at the bottom of the structure from which people extract the water for its use. However this invention, which produces 95 liters per day, is mainly used for small remote communities in the arid areas of Africa.
3. Airdrop Irrigation: This technology allows the irrigation of crops using only water extracted from the air. Utilizing a turbine intake system, air is channeled underground through a network of piping that quickly cools the air to soil temperature. This process creates an environment with 100% humidity, from which water is then harvested. The water is then stored in an underground container ready to be pumped out via sub-surface drip irrigation hosing.
Innovation has also led to the construction of technology that allows humidity harvesting to support large communities. Such a technology is known as “Aquasphere”. Aquasphere, which can produce around 100,000 liters per day, uses the Water Extractions and Purification technology (W.E.P.S) as a method of extracting water from the air. In an interview with Hisham Fawzi, the creator of Aquasphere, he stated that Aquasphere technology is fully capable to support entire cities. However, unlike the aforementioned techniques, it can be quite costly. Hisham insists that implementing this technology is “not just an investment for the future; it goes deep into the individual’s wellbeing”. “Governments cannot put a price on the wellbeing of its citizens and Aquasphere technology is a way that can reduce the number of human beings affected by diseases contracted from consumption of unclean water” Hisham adds.
What to make of it all:
Humidity harvesting has been adapted to suit the needs of various scenarios. It can be implemented on a small scale where it is used as a source of fresh water to remote villages, and on a big scale where it can be used to provide water to entire communities. Therefore, technologies and techniques such as these have the capacity to significantly improve the availability and access to clean water in water scarce regions like MENA. However, in order for this scenario to become a reality governments and municipalities in different countries must take the initiative to invest heavily in humidity harvesting. Only then can mankind be closer to solving worldwide water scarcity.