Bananas could purify water in the Amazon

During World Water Week, we spoke with changemaker Maricela Granda, a 25-year-old environmental biotechnology engineer from Ecuador who is developing a way to purify water using banana waste.

Granda comes from the Sucumbios province in the northern part of the Ecuadorian Amazon, known for its oil production. Her community is employed mostly by oil companies, as well as in agriculture—and bananas are an important local crop.  

It was while harvesting bananas on her parents' land that Granda observed the detailed structure of the pseudostem—the part of the banana plant that looks like a trunk—as it lay discarded. 

She also found that water in the area was polluted by hydrocarbons—as found in oil—with detrimental impacts on drinking water.

Granda used her expertise to investigate whether the banana stem could be used as an absorbent material to soak up hydrocarbons in the water. Her idea was to make a filter which could be installed in local houses to bring clean water to communities in areas affected by water pollution. 

Lis Mullin Bernhardt, Freshwater Expert at the UN Environment Programme (UNEP), said: “Having water of both sufficient quantity and quality is essential for the health of freshwater bodies like lakes and rivers, with direct impacts on human health.

“To tackle the global freshwater crisis, we need to find innovative, low-cost methods for water management which are readily available wherever needed. This sounds like an exciting example of such a method.”

We spoke with Granda to find out what inspired her idea, and what advice she would pass on to other young entrepreneurs.  

After you were inspired to tackle water pollution, how did you take your idea forward? What is your technology?

 My idea was to purify water from hydrocarbon pollution using the banana pseudostem. Water must pass through the filter that contains the banana biomaterial—and now we have added other materials that complement the filtration—such as gravel and sand to allow additional filtration. Currently, we are working on a final biofilter design, to ensure that our filter meets all parameters to ensure water quality. Water quality tests are performed before and after using the filter. The results are compared with the national technical standards that are subject to the standards of the World Health Organization.

Who are you working with to bring your idea to life?

I am working with universities and institutions in my community, to expand the research and apply a pilot testing phase. I am linking with other young people to exchange knowledge and experiences. I am also collaborating with organizations and groups who monitor pollution events in the communities where I want to work. We collect information from contaminated areas and then we compile an archive of pollution events and their effects. The idea is to have a collection of evidence for contamination, which will be the basis for proposing solutions such as biofilters to purify water in affected areas.  

How has your idea changed over the time you have been researching it?

When I began this project, much of my work focused on bringing knowledge from the classroom into reality. The aim was initially to install an effective biofilter design in community homes, to deliver cleaner drinking water. But now, we expect this to be part of a broader project on biomaterials, to understand how materials of natural origin can address pollution. I have met many people who have shared their knowledge and experiences, and participated in training workshops while discovering new opportunities for competitive funding. Above all, I have discovered new ideas that we can bring to life, and the project has been filled with inputs and strengthened. I no longer see our solution as just a filter, but as part of a larger water management plan.

What is the bigger problem you are now tackling?

By knowing what happens to water and where it is contaminated, we can work with those who make decisions that impact the community and their daily activities. Now we know how pollution affects the wider ecosystems that surround us, especially in a region as fragile as the Amazon, and we can work on bigger solutions with the whole community. While our filter currently targets contaminated areas, I now realize that more in-depth approaches are required to manage water in the whole ecosystem in the long-term. Now, I am working with a wider community to implement long-term water management solutions, of which our filter is one.

What is your advice to other young entrepreneurs?

Start with an idea, however small, and then work on clarifying it. And, always keep in mind that the idea may change—that it may be part of something much bigger. Start looking, surround yourself with people you can learn from, strengthen your knowledge, train and teach others. It is always good to share the seed of your idea, because if you keep it to yourself, you may not move anywhere. 

Maricela Granda is a Young Champion of the Earth changemaker. The Young Champions of the Earth Prize, powered by Covestro, is the UN Environment Programme's leading initiative to engage youth in tackling the world's most pressing environmental challenges. Winners are announced in September. Stay tuned!