Whilst demand for fresh water is increasing, water sources are becoming depleted and polluted. With the Global Water Partnership believing that sustainable development will not be achieved without a water secure world, can we look to space to solve our water security problems on Earth?

Recycling water on the International Space Station
Recycling water on the International Space Station

The more that astronauts can recycle, the fewer supplies they need to take into space. For almost three decades, ESA has been leading the development of a self-sustaining, waste-recycling ecosystem for use in space; the Micro-Ecological Life Support System Alternative (MELiSSA) aims to provide food, water and oxygen for crewed space missions.

The technology developed through the MELISSA project has also been applied to building a more sustainable planet. To mark World Water Day 2021, we focus on some examples of applications that are contributing to advancing global water security.

Fresh water in Morocco

The self-sustaining water filtration system providing fresh water in Morocco
The self-sustaining water filtration system providing fresh water in Morocco

Through MELiSSA, organic and ceramic membranes were developed to filter astronauts’ wastewater. Containing holes measuring just one ten-thousandth of a millimetre across – 700 times thinner than a human hair – these membranes can filter out unwanted compounds in water, in particular nitrates.

The same technology is used to treat groundwater for a school in Morocco. The village of Sidi Taïbi near Kenitra, 30 kilometres from Morocco’s capital city Rabat, has grown rapidly in the last two decades. Providing fresh water to its inhabitants is difficult because the groundwater is so rich in nitrates and fertiliser that it is unsuitable for human consumption.

With help from a UNESCO partnership, the University of Kenitra sought to apply the membrane technology to tackle their drinking-water problem. Building on ESA’s experience, French company Firmus teamed up with Germany’s Belectric to build a self-sustaining unit powered by solar panels and wind energy.

Worldwide waste treatment

The Semilla Sanitation Hubs’ unit at ESA’s Open Day in 2019
The Semilla Sanitation Hubs’ unit at ESA’s Open Day in 2019

Also based on the membrane technology, SEMiLLA Sanitation Hubs provide toilet and washing facilities that recover and treat wastewater for continuous use. A unit was available at ESA’s Open Day in 2019, where visitors could enjoy some tea and learn about the closed water loop.

Used water, termed ‘grey’ (from washing up and showers), ‘yellow’ (urine) or ‘black’ (excrement) depending on its origin, is processed into hygienic water through a cascade of technologies. Diluted water molecules are further filtered out through the process of reverse osmosis, in which fluid is drawn through a membrane that only allows particles of a certain size to pass. Once the water has passed through the various types of filtration, the procedure ends with UV irradiation to kill the remaining bacteria and impurities. The water should then be ready for reuse.

The company behind the sanitation hubs, SEMiLLA IPStar is a MELiSSA technology transfer partner. This means it applies MELiSSA technologies to Earth-based needs, including water treatment and waste management and recycling. Another project that SEMiLLA is working on is recovering water, energy and nutrients from urban wastewater in New Delhi, India. Specifically, these technologies are being incorporated into a modular pilot treatment plant along the Barapullah drain.

Electrifying water

The URIDIS system developed by Hydrohm based on MELiSSA technologies
The URIDIS system developed by Hydrohm based on MELiSSA technologies

A company called Hydrohm is also developing technologies for safe and sustainable toilets. The closet-sized URIDIS is a water treatment technology, the core of which was developed through the pool of MELiSSA PhDs (POMP) programme. URIDIS has two functions – taking valuable components from urine (phosphorous, nitrogen and salt) and pre-treating toilet flushing water to disinfect it.

Hydrohm was established in 2020 to develop electrifying water treatments as an opportunity to shift towards more local and sustainable water systems, with an increased focus on quality and health. As an alternative to treating water using chemicals, using electricity is renewable, economical, leaves no residue and can be done anywhere that there is an electricity connection. This makes it vital for countries hardest hit by a lack of water, which tend to be developing countries.

Optimising water use in hotels

Concordia research station at night
Concordia research station at night

Hotels often use huge amounts of water, little of which is recycled. The MELiSSA consortium brought together partners, including Sherpa Engineering, to develop a grey water recycling system called AIGANOVA. The aim was to optimise the use of water and minimise the cost of a water facility in hotels and other places that use a lot of water. AIGANOVA was developed based on MELiSSA expertise already employed at the Concordia research station in Antarctica. It addressed two major societal concerns – water consumption and energy use in water recycling – and demonstrated the possibility to reduce external water resources by 50–80%.

AIGANOVA was tested at a Balneotherapy Center hotel for 240 guests, where it was demonstrated that the facility could enable 60% of water to be recycled and would bring an annual gain of 80 000 EUR.

Space tech at the French Open

Water recycling at the French Open
Water recycling at the French Open

Every tennis player who took a shower at the Roland Garros training grounds in 2020 helped preserve drinking water. Harnessing technology originally developed through MELiSSA, a recycling system was installed by start-up FGWRS. This enabled wastewater from showers to be reused for flushing toilets, replacing the drinking water usually employed for this purpose.

The same technology has been used in Concordia for the last 15 years. It has been commercialised by FGWRS through the system they are named after – the Full/Firmus Grey Water Recycling System. FGWRS targets the preservation of drinking water resources by recycling up to 80% of grey water for reuse for toilet flushes, washing machines and other household tasks. The recycling system in place at the French Open in 2020 will also be present in 2021 and 2022, with the technical teams planning ongoing improvements, in particular to recover energy from this grey water.

Water recycling for Trappist brewery monks

Consecration of a bottle line at La Trappe Abbey brewery
Consecration of a bottle line at La Trappe Abbey brewery

When the monks from La Trappe Abbey brewery in the Netherlands wanted to make their beer-brewing process more sustainable, they chose a suite of techniques developed for MELiSSA to renovate their factory and recycle more water. The brewery produces almost a million cubic meters of wastewater each year. Thanks to the new recycling techniques this water is no longer being sent to a municipal processing plant but is used to irrigate the monks’ land and clean beer bottles.

The system recovers water and purifies it using membranes. An added bonus is that the system also reduces the brewery’s electricity use. The project at La Trappe was awarded the innovation prize of 2018 by the Dutch councils of municipal water.

All the examples mentioned in this article are space spinoffs that are helping to achieve the United Nation’s sixth Sustainable Development Goal of clean drinking water and hygienic sanitation for all.

Human and Robotic Exploration in aid of SDG6
Human and Robotic Exploration in aid of SDG6

-ESA also photos

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