On the World of Water Day, the United Nations unveiled its most ambitious bid yet to solve one of the world's most pressing challenges.

Number six on its list of Sustainable Development Goals (SDG) is an aim to ensure access to clean water and sanitation for all by 2030.

Key to efforts to achieve the ambitious goal – known as SDG6 - has been the development and adoption of nanotechnology.

According to a report by Maximise Market Research, the size of the nanotechnology in water treatment market was valued at over $1.6 billion – a figure it predicted would grow by 9.1% a year, reaching nearly $2.7 billion by 2027.

That is fuelled by heavy investment in nanotechnology research in the sector by governments, private companies, and non-profit organisations.

According to a report by the National Nanotechnology Initiative (NNI), the US government had invested more than $1 billion alone between 2005 and 2016 into nanotechnology research for water and sanitation treatment, part of a $10 billion package it has invested in nano so far.

Nanoparticles and nanotubes are being deployed as absorbents and catalysts to remove pollutants from water.

It reduces the chance of illness and enhances the potential for people to become more self-sufficient and also, in the long term, helps reduce poverty. By alleviating the strain on resources – which often triggers conflict – it also hoped to help ease tensions in key areas while also buoying employment prospects.

A commonly used nano-based water purification process is nanofiltration.

With a pore size of around 0.001 micron (one micron equals one-millionth of a meter), nanofiltration removes most organic molecules, nearly all viruses, most of the natural organic matter, and a range of salts.

The process also removes divalent ions, which make water hard, so it has a wider commercial use as a water softener.

The company Aquaporin is already rolling out the technology globally.

Explains the company: "Water is essential to all life on Earth. But our water resources are limited, and they need to be cared for and responsibly used.

"Our goal is clean, natural drinking water for all and the sustainable reuse of water in industrial applications. We're using aquaporins – the super water purifiers found in every living cell – to make it happen. It's a revolutionary idea based on billion-year-old natural technology, and we believe it will change the world."

It is estimated by the UN some 2.2 billion people lack access to safely managed drinking water, and more than 4.2 billion people lack safely managed sanitation. Climate change is exacerbating the situation with increasing disasters such as floods and droughts.

In addition, conflicts around the world can devastate infrastructure – with water supplies often hit. Nano can help overcome that.

The UN adds that 80% of wastewater in the world flows back into the ecosystem without being treated or reused, and 70 percent of the world's natural wetland extent has been lost, including a significant loss of freshwater species.

But, of course, that is only one cog in the battle to ease global poverty.

Another where nanotechnology – the global market is already valued at over $54.2 billion and is expected to reach $126.8 billion by 2028, according to a report by Grand View Research - is playing a key role in healthcare and vaccines.

Australian company Vaxxas uses its HD-MAP technology to provide a needle-free solution and one which avoids the need for vaccines to be stored at certain temperatures in areas of the world where access to refrigeration is a challenge.

It uses a patch with thousands of vaccine-coated micro projections that is applied to the skin for a few seconds to efficiently deliver a vaccine to the abundant immune cells immediately below the skin's surface.

Already validated in human clinical studies, one of its key aims is to "extending the reach of global health vaccine needs in low-and-middle-income countries".

Nanotechnology can also be used to improve the efficiency of agriculture and increase crop yields. For example, the development of fertilizers and pesticides that are more targeted and effective reduces the need for harmful chemicals and improves crop yields.

Unsurprisingly, number one of the UN's SDG list is eradicating poverty.

Adds Aquaporin: "The UN's SDGs have a huge potential for companies around the world. Business has a key role to play in achieving the goals because the world needs its solutions if the world's biggest challenges are to be solved by 2030.

"The goals represent a huge economic opportunity - when people around the world overcome poverty and are protected from hunger, disease, and exploitation, and they gain financial profits. It opens new markets for companies around the world.

"According to the Better Business Better World report by the Business & Sustainable Development Commission, achieving the SDGs by 2030 will open up the new market potential of $ 12 trillion a year in the private sector worldwide."

Water resources have also been successfully utilized safely and sustainably via The Portuguese Institute for International Iberian Nanotechnology in Braga, using nanotech-based sensors to monitor water quality and create nanomaterials that can specifically remove harmful substances from water.

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