Bottle cleans water with blue light: invention could benefit millions

At the age of 28, she received national and international awards from Red Bull Basement for creating a bottle with a built-in solar battery that eliminates bacteria and microorganisms from the water through blue light radiation. A year later, environmental engineer Bárbara Gosziniak Paiva takes the last steps before launching the bottle on a commercial scale.

“When the project broke in the media, it was still very raw. We still didn’t know the essential dose to carry out the treatment. Now we have a much clearer view, we already have the data to actually build the bottle. All it takes is getting the partners and the investment and we should start manufacturing,” says Bárbara, who presented details of her invention at the 78th Official Engineering and Agronomy Week (Soea), in Gramado (RS).

The use of ultraviolet light as a sterilizing agent for surfaces and objects has been studied for decades, and has gained new momentum in the fight against the spread of Covid-19, starting in 2020. Bárbara is among the pioneers in studying radioactive waves, with a wavelength of 450 nanometers, to purify water.

Challenge is to sterilize large volumes in less time

The potential of blue light (ultraviolet rays) for water purification, on a larger scale, such as water tanks or tanks, will continue to be the subject of study by Bárbara at the Federal University of Ouro Preto (UFOP), now in a doctoral thesis. One of the difficulties in sterilizing large volumes of water is the time required for exposure to radiation, currently 3.5 hours, to ensure that all pathogens are killed.

The word radiation can scare lay people, but the researcher explains that the level used is harmless to human beings. “This radiation problem will depend on the wavelength. When the wavelength is very low, we have very high energies, like gamma radiation, which really causes problems for us. But when we increase the wavelength, the energy of this radiation decreases until it reaches radio waves, for example, which have a very low energy and a very high wavelength”, he reassures.

The decision to look for alternative ways to the use of chlorine for water treatment was taken on a trip by Barbara to New York, when she was impressed to discover that people drank tap water, without filtering it. “Why in Brazil do we need to filter water when it reaches the tap? Why don’t we preserve the watershed? Why in college do we only study conventional methods of treatment and disinfection?”, were some of the questions that reverberated in the researcher’s head.

Blue light is effective against bacteria It is. coli

Back in Brazil, the use of blue light to sterilize water, and the design of a self-cleaning bottle, became the subject of master’s research at UFOP. The bottle, with solar battery, also comes with a membrane to filter out solid particles. “The membrane serves only to avoid the shadow, because if there is a shadow on the microorganism, the light will not reach it. The bottle is capable of killing all microorganisms, including bacteria escherichia coliwhich is a major cause of diarrhea and disease”, he emphasizes.

At first, Bárbara’s invention is aimed at athletes and campers, ensuring that water from sources and streams can be safely ingested in terms of organic contamination, which is more frequent. The idea, however, is to extrapolate the application of the technique, benefiting millions of people.

“These microorganisms cause several diseases and deaths in the world. And the problem is more recurrent in poorer populations, who do not have access to sanitation, which would prevent the arrival of these microorganisms into the water, or to water treatment”, he observes.

“If the water is contaminated with heavy metals or excess chlorine, it is not the bottle that will solve it. Even so, it will already be applied to a huge universe of situations”, adds Bárbara.

The invention of the young woman from Minas Gerais, Aqualux, is patented. Investors are still missing.

*The journalist traveled to Gramado at the invitation of the Federal Council of Engineering and Agronomy (Confea).