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UDLA Student Develops Innovative Wastewater Purification Project


An innovative and environmentally friendly purification system using natural materials found in Ecuador has been developed at Universidad de las Américas. After a series of experiments, Francisco Cevallos, a student of Environmental Engineering at UDLA, claims earthworms can be a key component in the water purification process.

Water recycling is becoming a common feature  in homes in other South American countries, such as Bolivia, Argentina and Chile. In fact, it was while he was in Chile on a student exchange program that Cevallos came up with the idea. He then took initiative and began implementing similar purification systems on his return to his native Ecuador.

“Earthworm” Bio-Filter

In Quito, Cevallos conducted a series of tests using a compost containing earthworms and seeing how they survived in different conditions, whether it be temperature, humidity, altitude, or extreme climate change, etc. After 80 days of experimentation, Francisco found the bio-filter system viable, economical, ecological, practical and easy to apply.

Wastewater samples were taken from the Metropolitan Canal. Students collected 200 liters of contaminated water on a daily basis and drained it into the compost, of which 150 liters was purified i.e. 24 liters between 6 tanks. The tests concluded that the bio-filter system actually obtained a higher level of purified water than what is usually required by state guidelines, which stipulates that water extracted by sewage must have a maximum level of 200 milligrams of DDBO5 (Biological Oxygen) per liter. Quite remarkably, experiments showed that purified water obtained only 150 milligrams of DBO5 using the same amount of liquid, therefore proving that the bio-filter system is more effective than the traditional purification systems using organic waste.


A more economical and ecological approach than traditional purification systems, using Ecuadorian materials not usually recognized as natural “purifiers”.

Natural Materials

Cevallos also used extracts from natural Ecuadorian materials. One of those was pumice stone, an innovative material that is commonly found in the country’s rivers, and never been used before as a “traditional” purifier.

Another interesting extract used were eucalyptus leaves taken from Quito’s Metropolitan Park. This raised a few eye-brows, as it is scientifically proven that nothing much grows with this type of biodegradable material. However, the earthworms not only survived, but also maintained their normal life-cycle.


The bio-filter system also has economic advantages, since traditional purification systems cost between $100-150 per cubic meter of water, while this system only costs $70 producing the same amount of liquid.

Another advantage of the bio-filter system is that it produces residences that can be reused for agricultural use. The more traditional purification techniques, meanwhile, produce mud and pellets, etc. which later needs screening process to ensure it is not contaminated.

The aim is now to implement the project with a more business scope, by concentrating on industries produce an excess of organic waste liquids, such as dairies, dairies, breweries, etc.

As you can see, projects such as this not only puts on the display the academic excellence at UDLA, but it also seeks to create professionals capable of developing initiatives and proposals to solve local and national problems.

If you feel inspired by Francisco Cevallos’s work, visit the UDLA website and browse the online brochures.

About the Author

Universidad de las Américas Ecuador

Since 1994, Universidad de las Américas (UDLA) offers its students a top academic program. Our curriculum is managed under international standards, thus ensuring a comprehensive education that allows our graduates to be ready to face any professional challenge.