The world needs pure water, but the effects of climate change such as drought and intense downpours that risk contaminating groundwater supplies, mean it is becoming ever harder to source. With global warming accelerating, research scientists are racing to find new water purification and conservation technologies that could protect the planet and save lives.
Extreme weather events, such as the recent floods in Pakistan and the drought affecting large areas of central Asia and China are becoming more frequent, bringing hardship in the form of famine, wildfires and disease to communities around the world. Even in the UK, which is known for its temperate climate, record summer temperatures have damaged crop yields and caused the soil to dry out due to excessive heat radiation, increasing the likelihood of flash flooding.
Increased awareness of changes affecting the natural environment and growing public concern about groundwater depletion and contamination is driving innovation activity to find novel ways to protect communities and food crops in the future.
In the UK, policymakers have begun to show interest in tightening regulatory controls to promote water conservation, and while developers are not yet required to consider the impact of their construction projects on groundwater supplies, they could be forced to do so in future. Natural England, a publicly funded organisation that advises the UK Government on policy matters related to the natural environment, has provided a definition of ‘water neutrality’, which could be adopted to ensure that new developments don’t increase the rate of water abstraction for drinking water supplies above existing levels.
A key area of concern in this space is the risk of contamination of underground water bodies, known as aquifers, due to rising sea levels or increased land runoff during periods of drought. Aquifers are of vital importance, providing half of all water for the domestic use of the global population and around 25% of all water for irrigation. To protect these valuable subsurface supplies, innovators are developing technologies such as Super Absorbing Resins (SARs) to aid in groundwater retention and soil improvement, and new membrane technologies to remove harmful contaminants.
Elsewhere, research scientists are focussing their efforts on more efficient ways of desalinating seawater to reduce our reliance on dwindling fresh water supplies from streams, rivers and underground aquifers.
Currently, the vast majority of desalination of ocean water uses one of two methods. ‘Flash distillation’ involves applying intense heat to sea water in multiple stages to cause a ‘flash’ of steam, which is subsequently condensed into pure water.
An alternative process known as ‘reverse osmosis’ involves using high pressures to force water across a semi-permeable membrane that filters out salt and other contaminants. Due to its much lower energy consumption, reverse osmosis has become the dominant method and is used at almost all new treatment plants around the world. However, reverse osmosis is still an energy-intensive process, due to the intense pressures needed to push the water through the membrane, and more energy is needed if the salt concentration of the feed is high.
Research scientists at the Saline Water Conversion Corporation (SWCC) in Saudi Arabia have developed an eco-friendly way of achieving desalination, which uses ‘ocean thermocline energy’, or naturally occurring temperature differences between surface seawater and deep seawater, to drive the process. The patented technology (US20210221709A1) involves an arrangement in which a membrane and an air gap is sandwiched between the flow of warm (shallow ocean) water and the flow of cold (deep ocean) water. As the warm seawater passes along the membrane, the partial pressure differences due to the temperature gradient push water vapour through the membrane into the air gap. The vapour condenses in the air gap due to its proximity to the cold seawater. Optionally, a vacuum can be used to draw air out of the air gap, and solar panels can also be used to further increase the temperature of the surface seawater as required.
Another focus for innovation activity has been the material used to create the membranes for use in reverse osmosis. Danish company, Aquaporin, has recently been granted a European patent (EP1885477B1) for its novel membrane technology, which is inspired by nature. The technology uses water transport proteins or ‘aquaporins’ to filter water faster and more energy-efficiently. These aquaporin proteins form a lipid bilayer within the membrane. This biomimetic membrane can be used to desalinate seawater without the need for electricity or desalination chemicals.
The current focus on desalination technologies has also led to greater interest in finding a more sustainable way of disposing of its key by-product, brine. Research scientists at MIT have developed a means of converting the waste material into useful chemicals, such as caustic soda or sodium hydroxide, which can also be used to improve the efficiency of the desalination process.
From an intellectual property perspective, the global nature of climate change makes it even more important than usual that innovators seek patent protection in all principal markets. By seeking advice on their global IP strategy at an early stage, they can secure a stake in a fast-moving market and avoid the risk that copycat engineers develop a rival solution that beats them to it. The ultimate end user of the technology is likely to be large corporate entities or government bodies, so commercial use will often involve licensing. With rights ownership in place, innovators can choose to license their technologies at very low rates or offer royalty-free licences to projects in developing nations. Due to the reliance on a licensing model, a multi-layered approach to intellectual property protection, incorporating both patents and other registered rights is advisable.
The United Nations claims that some 80 percent of the world’s water flows back into the environment without being treated or reused. Add to this the effects of climate change, which increase the risk of groundwater contamination, and the situation is only going to get worse. Innovators are working on some promising solutions, but they can’t come quickly enough.
Dr Joanna Thurston is a partner and patent attorney at European intellectual property firm, Withers & Rogers. She is also a lead member of the firm’s Cleantech group.
