Anna Luisa Beserra is currently known as an environmental entrepreneur. But before she went into business, she was an environmental changemaker. At just 15, she came up with Aqualuz, a system that uses just sunlight to eliminate microorganisms in rainwater without chemicals or complex filters.As a teenager, Beserra was motivated by the lack of clean drinking water for millions of people in Brazil and decided to do something about it. “I knew then that if I created something easy to use and replicate, communities could take control of purifying their own water,” Beserra told UNESCO.The system created by Beserra, called Aqualuz, is affordable, sustainable and designed to last up to 20 years, offering a lasting alternative to temporary filtering solutions. The technology was designed for families relying on rainwater cisterns in semi-arid regions and is already in use in rural Brazil, benefiting more than 10,000 people and reaching 40,000 in 2024 alone.The idea was simple yet precise. Aqualuz is a rainwater treatment system that uses solar radiation to purify collected water safely and affordably by killing microorganisms. The device gave rural households a way to secure clean drinking water without depending on expensive infrastructure or unreliable municipal systems.According to Beserra, scientific research is essential, but it cannot replace firsthand experience with communities. “Meeting families facing water scarcity changed the way I approach solutions. Nothing replaces learning directly from the people you’re trying to help,” he said.Her approach includes training local technicians to lead the installation and monitoring of the systems, making each project a shared effort.Over the years, Beserra, a native of Salvador in Brazil, has earned a degree in biotechnology at the Federal University of Bahia. She has refined the prototype of Aqualuz into a working model and built a social enterprise around it. Today, she is the founder and CEO of Safe Drinking Water for All (SDW), a Brazilian company that designs affordable sanitation and water purification technologies for underserved communities.Beyond Aqualuz, Beserra has developed other solutions such as Aquasalina, which uses sunlight to desalinate water; Aquafilter, a filtration system for communities of up to 100 people; and Aquatorre, designed for schools and areas without water infrastructure.Her goal is to expand these technologies across Latin America, Africa and Asia, providing sustainable access to safe drinking water while strengthening education and local communities’ independence. For her work, Beserra is recognised by the UN, UNESCO and MIT.