27 March 2025
Magical. That is how we would describe our time at the Stockholm Junior Water Prize (SJWP). This is a word thrown around often, but in Sweden, it could not be more accurate: late-night roaming with newly made friends in the fairytale Old Town; spellbinding talks from behemoths in the sustainability space accompanied by deeply enriching conversations; a meeting and banquet with the Swedish royal family.
Our research journey began in December 2023, and after months of traversing the estuaries of the Thames and immersing ourselves in experiments and field trips, we were ready to present to the UKJWP panel. Our project, PFASolve, provides a system to detect and filter PFAS from the Thames basin. PFAS, colloquially known as ‘forever chemicals’, are by-products of many industrial processes that have century-long half-lives and persist in ecosystems for decades.
The problem associated with PFAS is twofold. First, they are highly carcinogenic, leading to conditions such as kidney and liver cancer at microscopic concentrations of four nanograms per litre. Second, awareness and regulation of these chemicals are severely lacking in the UK.
We therefore designed a machine learning model that predicts PFAS concentrations based on a user’s coordinate location (or, more formally, a geospatial neural network). We compared the model’s predictions to real-life concentrations from samples collected from Richmond, London Docklands, and Battersea Power Station, achieving a 94 per cent accuracy rate. We also designed a cheap point-of-use filter that optimises the size and type of granular activated carbon (a common filter substance) to ensure a 93 per cent decrease in PFAS, while minimally impacting the user’s experience. It’s easy to install on a tap.
Through this concurrent mechanism, we hoped simultaneously to evoke a personal urgency – allowing anyone to access data about PFAS concentrations around them – while providing a solution, thereby increasing political impetus for addressing this problem.
This opportunity was hugely valuable. Outlining and refining the idea for pitching helped us characterise our research more precisely.
After being announced as the winners of the UK round, under the careful guidance of Marieke Muller, partnerships manager at CIWEM, we set off to Stockholm in late August for the 2024 World Water Week, a research conference bringing together thousands of hydrologists, regulators and activists.
Arriving in Stockholm, we weren’t just greeted by beautiful nature and architecture – we also found a community. We eased seamlessly into a group of 40 students from 30 countries, with team-building activities and typical Swedish food accompanying conversations that were both authentic and intellectually rewarding. The presentations to the international jury – composed of tenured professors and UN ambassadors – though nerve-wracking at times, were cushioned by a camaraderie that had developed between us and the other competitors. The experience felt more like a culmination of our journey rather than a high-stakes competition.
We then had access to the rest of the conference, giving us the privilege of engaging with a host of experts and being able to hear seminars on developing leadership and communication – skills that are at the heart of promoting sustainability. The next two days were filled with guided tours around Stockholm, study visits to the headquarters of Xylem (the competition sponsor) and preparation for some of the formalities of the prize.
The first of these formalities was the award ceremony, which featured a patriotic flag parade with all the contestants dressed in black tie or their national dresses, as well as musical interludes and keynote speeches by figures in the wider World Water Week.
We went into the ceremony with zero expectations for winning, having seen some of the incredible work of the other participants. It was therefore a shock when our names were announced and we were invited to the stage to shake hands with Victoria, Crown Princess of Sweden and receive our certificate and crystal trophies. We were also asked some questions about our project in front of the audience in person and online.
Following the ceremony, we had a delightful conversation with the Crown Princess, who was very understanding of our flustered responses. We were then bussed to the Skansen open-air museum, where we were treated to a private tour of the grounds and a laid-back dinner with our friends. The whole evening was euphoric.
The days following the ceremony were somehow even more special. We were invited to the Stockholm City Hall – where the Nobel Prize banquet is held – to celebrate the winner of the Stockholm Water Prize, awarded to a hydrologist who has contributed greatly to water research in the world. We listened to inspiring speeches by King Carl XVI Gustaf of Sweden and Professor Taikan Oki, the 2024 SWP winner. It was potentially the most spellbinding evening of our lives.
Conducting research for the UK Junior Water Prize was a fruitful journey, with the international competition being the cherry on top. CIWEM provides the guidance and structure for any – initially inexperienced – high school scientist to undertake the research journey from start to finish. The end goal, a 20-page paper, summarises months of planning, experiments, analysis and reading, all of it motivated by entering the UKJWP. Additionally, we fostered connections with the jury members – distinguished industry experts from CIWEM, Jacobs and Arup – who have continued to guide our project.