Published: 07th February 2018
What it takes to quench thirst in a world where water is becoming scarce
Harvesting water in areas that may be falling short of water supply is considered the next step in water management and production
Water is crucial to our society and for sustaining our ecosystem. To know the importance of this career, it is important to understand the problem of fresh water scarcity. Approximately 98% of water available on Earth is salty and unfit for consumption. This means that only 2% is fresh and fit for use. It has been estimated that by 2025, there will be over three billion people without adequate access to potable water.
Our poor water management techniques, weak water policies and the looming threat of climate change has created this situation in which sooner or later, we will have to come up with alternative sources of generating potable water. Dew water harvesting is one such emerging opportunity. It requires expertise in controlling vapour-to-liquid phase transitions.
Harvesting change: Anil was a member of a team consisting of Indian scientists and experts from France who developed a technology for harvesting dew
The water from moisture is the purest form of water, and it does not require heavy investment or any other traditional, mechanical or electrical industries. It comes in several derivatives such as rainwater harvesting, fog harvesting and dew harvesting. Dew harvesting is different from rainwater harvesting. It requires an understanding of surface science and how to maximise the yield of conversion of vapour into water.
Understanding of liquid-to-solid phase transition becomes critical in cases of ice storms. These ice-storms cost us billions of dollars each year, besides the loss of human life. Air bleeding is a standard process to prevent the formation of ice on aircraft wings. It consumes up to 5% of energy to avoid this kind of icing during a flight. This has an additional $2.5 billion burden on Avionics. The energy generation through wind turbines in areas like Sweden and Iceland is also impacted by this phase transition. This speaks about how promoting or blocking a phase transition process has a phenomenal impact on the technological landscape that results in multibillion-dollar market opportunities.
This harvesting is based on the condensation process which requires an understanding of phase transitions, a subject of thermodynamics and surface science
Currently, dew harvesting is a challenge and therefore it does not seem like a lucrative business model. It is expected that a textured surface may enhance the productivity and then this area may become an attractive business opportunity for students. The surface chemistry and topography of textured surfaces need to be perfected so that maximum dew can be converted into water. Collection of this water and purification or filtration before packaging it for use does not require much investment. The challenge is that currently, there is a dearth of fundamental thermodynamic understanding of phase transition on textured surfaces.
With progress in the areas of manufacturing of nanosurfaces, it looks doable that if such surfaces can be created by giving texture at the microscale, then it is possible that the output of harvesting will improve. We hope that soon, with the government’s focus on countering climate change and looking for more alternative sources of potable water doors will open for dew water harvesting and make it a lucrative business opportunity for all.
(Hari Balaji hails from Chennai, India and is an alumnus of the Swiss Hotel Management School, Switzerland and Sri Ramachandra University, India. He has served as a consultant and master trainer for UNICEF and UNFPA in different parts of India. He regularly conducts orientation programmes and workshops in India’s premium institutions including IIT Madras. As a State Manager for flood response and coordination, he has coordinated rescue and relief efforts with various local, state, national and global agencies. In recognition of his contribution during the Tamil Nadu Floods 2015, he received the ‘Bhale Bharath Award of Excellence’ by the Indian Science Monitor. He is certified by the World Health Organisation (WHO) for ‘Emergency Risk Management’ as a Master Trainer for Minimum Initial Services Package (MISP) for Sexual and Reproductive Health during Disasters by UNFPA.)