Multisensing device maps water contamination in rural Colombia

An electrochemical device developed at Bath University is being used in rural Colombia to detect water contamination and help map problem areas.

The device measures four key physicochemical variables in water, namely pH levels, conductivity, temperature and dissolved oxygen. It also monitors the presence of heavy metals in water, including mercury. Developed in conjunction with Colombia’s University de Los Andes, the system features a mobile app that uploads the readings in real time to a web-based platform. This allows authorities and members of the public to see where contamination is at its worst, potentially tackling its root causes.      

“The novelty of this device lies mainly on the electrochemical detection and on the interactive process and display of the data,” Dr Mirella Di Lorenzo, project lead and senior lecturer at Bath’s Department of Chemical Engineering told The Engineer.

“The device is an integrated sensor that includes probes for physicochemical analyses, together with electrochemical detection of heavy metals [mercury, lead, copper and cadmium] using screen-printed electrodes. The sensor communicates with a smartphone and the data is sent to an open-access interactive map.”

Officially known as ‘Water Monitoring in Colombian Vulnerable Communities in a Post-Conflict Scenario’, the project was conceived with the express aim of addressing contamination in the Colombian Amazon. According to the Bath team, Colombia is the third most mercury-contaminated country in the world, largely due to illegal metal mining. Parts of the great river are highly polluted by the heavy metal, which finds its way into the food chain via fish consumed by locals, as well as irrigation and drinking water.

Rural indigenous communities have been particularly affected, with high rates of foetal malformations and brain disorders linked to the problem. As part of the project, the research team spent three weeks testing the device alongside the indigenous community of the Resguardo Santa Sofia, located at the southern tip of the Amazonas region of Colombia.     

“Due to the lack of financial resources and technology, communities like Santa Sofia in the Amazon have no means of checking if the water they are surrounded by is safe to use,” said Dr Di Lorenzo. “This multi-sensing device can have a massive impact to these communities, allowing them to easily check if the water they are using is safe to do so.”

The researchers believe that by mapping areas of water affected by mercury as well as providing locals with key water variable readings, the spread of water-borne diseases can be prevented. They hope that communities are empowered with a means of testing a water supply themselves whilst authorities are provided with evidence of water affected by illegal mining allowing them to act and mitigate this activity. Currently, the team is working to further improve the device by making it more intuitive and smaller, making the technology even more accessible for rural communities.

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