Seven innovative ideas for saving water.
From beer made from recycled water to growing tomatoes without soil, the Water Pressure exhibition at the Museum of Applied Arts in Vienna is all about saving water.
In addition to facts about water consumption, waste and scarcity, the exhibition WATER PRESSURE. Designing for the Future also presents innovative approaches to the treatment and reuse of this vital resource. DER STANDARD presents seven of them. The exhibition opens on 20 May at 7 pm at the Museum of Applied Arts (Mak) and can be seen until 7 September.
Draining water
According to the Ministry of Agriculture, the average consumption of drinking water in Austrian households is around 130 litres per person per day. A quarter of this is flushed down the toilet. To counteract this waste of water, the German start-up company Goldeimer has developed a so-called dry toilet. It is suitable for allotment gardens, as a camping toilet and generally anywhere where there is no water or sewage connection.
The toilet is not flushed with water but, like its Austrian counterpart Öklo, with either wood sawdust or the company’s own ‘poo powder’. The latter is said to prevent odours, absorb liquids, be biodegradable and consist of natural ingredients. However, there is no flushing in the traditional sense; instead, urine and faeces are collected separately in bags, depending on the model.
The designers at the Viennese studio Eoos also want to save the world a little with their Save! toilet. The model, which was developed in collaboration with the manufacturer Laufen, separates urine and black water (wastewater containing faeces and urine). The so-called substance separation toilet can remove 80 per cent of the nitrogen in the sewage system on site. The separation is invisible to the busy person, the designers promise. The idea is that while faeces and flushing water are sent to the treatment plant, the nitrogen in the urine can be processed into fertiliser.
Beer from wastewater
Admittedly, the idea of brewing beer from wastewater doesn’t sound particularly appealing. Especially when established breweries such as Weihenstephan set “high quality standards” for the composition of the water. According to their website, it determines nothing less than the character of the beer. The Ottakringer brewery in Vienna also pumps water from its own well. This is probably why water technology companies such as Epic Cleantec are focusing on beer in order to overcome prejudices against drinking recycled water.
In collaboration with Devil’s Canyon Brewing, they have brewed beer using recycled grey water from a large apartment block. It will not be available for tasting at the exhibition. But at least the cans can be inspected. The idea of treating grey water from residential buildings could be traced back to a law that came into effect in San Francisco in 2015. It requires large new buildings to recycle their water for toilets, irrigation, etc.
The exhibition explains that Singapore has a similar strategy and even treats all its wastewater to produce drinking water. In Austria, only seven per cent of drinking water is treated.
Germ-free water
Behind the unwieldy word xylem lies a plant tissue with some very interesting capabilities. Found in pine or ginkgo trees, xylem filters harmful bacteria out of water before they enter the plant’s cycle. Researchers at the Massachusetts Institute of Technology (MIT) in Cambridge have studied and replicated this process.
The result is the Detoxyfi filter, which uses wooden discs from ginkgo and pine trees to remove up to 99 per cent of pathogens such as E. coli and rotavirus from contaminated water. The natural filter works without chemicals and is biodegradable. It has already been successfully used to filter drinking water in New Delhi, India.
Let there be drinking water
The so-called water cone seems to be a real miracle. It makes it possible to produce drinking water from salt and brackish water independently of water pipes, cheaply and on the move. Brackish water is a mixture of fresh and salt water with a salt content of between 0.1 and one percent.
All you need for the Watercone is salt water, sunlight and a transparent plastic cone – designer Stephan Augustin chose polypropylene and polycarbonate specifically – which can be opened at the top with a screw cap. The base is a bowl with a drip tray. To obtain drinking water, salt water is poured into the bowl, where it evaporates in the sunlight, condenses and is then collected in the drip tray. The thirst-quenching piece is on display at the Mak Design Lab.
Floating agriculture
The exhibition breaks down water consumption in Austria. Industry accounts for almost 69 per cent, households and commerce for around 25 per cent and agriculture for just under six per cent. The so-called virtual water consumption is calculated for individual foodstuffs such as coffee, tomatoes or beef. This includes all the water used to grow, process and transport the food.
Beef consumption, for example, uses 484 litres of virtual water per person per day. Coffee consumption also uses 224 litres. Tomatoes, on the other hand, are less thirsty with a virtual water consumption of five litres. The population’s diet is responsible for around three quarters of the daily water footprint,” the exhibition concludes.
One concept that aims to save water and use it differently is hydroponics. This system uses water and minerals rather than soil to grow plants and, according to the Water Pressure exhibition, promises to use up to 70 per cent less water than traditional agriculture. The Jellyfish Barge model illustrates what this could look like. It is a modular greenhouse for urban areas that floats on water and draws energy and fresh water from the sun. In addition, the water used for cultivation is distilled from the water it floats on.
Colourful fabric
The figures vary, but they are staggering: between 80 and 150 billion items of clothing are produced every year. As a result, the fashion industry is responsible for between eight and ten percent of global greenhouse gas emissions. That is why Water Pressure is also focusing on the textile industry – specifically the process of dyeing fabrics. This consumes more than five trillion litres of water every year. Toxic petrochemical dyes are also used.
The start-up company Colorifix is working to develop non-toxic dyes. It will work with pigment-producing genes “identified by DNA sequencing, introduced into the DNA of microorganisms and cultivated by fermentation”. The technology uses less than half the water of conventional processes.
New building materials
Anyone travelling along the coast of the Persian Gulf will see one or two desalination plants. But there is a problem with this method of producing drinking water: According to the exhibition, “huge quantities of brine are discharged into the sea”. Wastewater brine is concentrated brine and the waste product of the desalination plants. Once back in the sea, it increases salinity, temperature and heavy metal concentrations, and damages the ecosystem.
As a solution, the Waiwai Research & Design Agency is developing magnesium oxide concrete as an alternative to cement. Such an alternative is needed anyway, as concrete production accounts for 1.7 percent of global water consumption and eight percent of CO2 emissions. (Julia Beirer, 20.5.2025)
