Phyto-remediation: the plants cleaning up the world’s polluted soils and water

What began as an experiment in the 1990s is today a technique applied in rural, urban and industrial landscapes the world over. Phyto-remediation demonstrates that the most powerful responses are sometimes to be found in nature itself

About the author

César Javier Palacios

Environmental journalist

César Javier Palacios is an environmental journalist, geographer, naturalist, and holds a doctorate in Art History. After an extensive career as editor-in-chief at Diario 16 Burgos and later at Claro, he contributed to El País and El País Semanal. He later relocated to Fuerteventura, working with Canarias7 and Agencia EFE.

His experience spans roles with the Doñana Biological Station (CSIC), SEO/BirdLife, Global Nature, the Fuerteventura Island Council, the national parks of Garajonay and Timanfaya, and the Biosphere Reserves of Lanzarote, La Gomera, and La Palma. He also served as Communications Director for the Félix Rodríguez de la Fuente Foundation and FSC Spain.

César is the host of El Señor de los Bosques (a nature and gastronomy program on Spain’s national TV channel La2). He writes a column for 20 Minutos, blogs at La Crónica Verde, and collaborates with RNE and Radio5. In the summer of 2024, he launched his own show, Músicas a Vuelapluma on Radio Clásica (a classical music station in Spain).

Meet the author

The Piccolo Sea is a precious Italian lagoon, much like the Menor Sea in Murcia or the Albufera of Valencia. A coastal lagoon with calm water separated from the Mediterranean by a narrow sandy bank with hardly a channel linking them. Its privileged location and wealth of fish saw it named a colony of Taranto by Sparta’s Greeks in 706 BC, making it an important city of Magna Graecia.

For centuries, it was a paradise. But now this fragile ecosystem is languishing due to industrial pollution. Thankfully, scientists have found a solution capable of returning life to the lagoon by using a simple but powerful tool: plants.

Thanks to the implementation of nature-based solutions such as phyto-remediation, the Piccolo Sea is experiencing a notable recovery.

What will I learn from this article?

What is phyto-remediation?

It sounds like a medical remedy – and that’s partly true. There are many successful treatments using plants that have improved medicine. Phyto-remediation is a series of technologies employing plants and their associated micro-organisms to clean, restore and recover polluted environments in land, water and the air. The process is based on the natural capacity of certain species to absorb, accumulate, degrade, destabilize or stabilize pollutants present in the environment, including heavy metals, organic compounds, radioactive materials, pesticides and oil derivatives.

It has its origins in the 1990s, when Ilya Raskin, a biologist at Rutgers University (New Jersey, USA), coined the term and demonstrated its potential using mustard seeds to extract heavy metals from contaminated soil around the Chernobyl nuclear power station in Ukraine.

This novel focus is today becoming a tremendously effective, sustainable and economic tool in the environmental regeneration of degraded natural spaces - and a beautiful symbol of hope, with noteworthy success in Italy and many other places worldwide.

Success stories in regenerating soils and water worldwide

The Piccolo Sea, nature as an ally in decontamination

The Piccolo Sea in Taranto is famous for the quality of its mussels. But this is an activity in danger due to the intensive industrialization process the city began in the 1960s, when it installed one of the biggest steel plants in Europe, a refinery and cement factory next to the sea.

The presence of heavy metals, hydrocarbons and other pollutants has seriously affected biodiversity and local economic activities, as well as residents’ health. This led in 2011 to the banning of mussel breeding in certain areas due to high levels of dioxins and PCBs.

Against this environmental challenge, scientists and local authorities have opted for phyto-remediation, the natural technique that uses plants to absorb and neutralize pollutants. They have planted species such as white poplar (Populus alba) and the common reed (Phragmites australis) in strategic coastal areas in order to reduce heavy metal concentration and other toxics present in water and sediment. Also, algae such as sea lettuce (Ulva lactuca) are helping in this task.

The presence of the plants has brought about significant improvements in water quality and biodiversity thanks to a focus not only less invasive and more economic than traditional mechanical cleaning techniques, but also promotes ecosystem restoration and renewed fishing activity.

The improved water quality, for example, has permitted mussel breeding to be restarted in previously polluted areas. The famous tarantino mussel, an emblematic product of the region, is being grown again after three decades of scarce production and it fully complies with food safety standards. Sea horses and fan mussels have also benefited from the changes.

Although the Piccolo Sea as a whole requires many complementary solutions, phyto-remediation has shown that it is possible to reverse decades of environmental degradation through a combination of solutions based on nature, technology and community participation. This integrated focus also serves as a model for the recovery of ecosystems affected by industrial pollution in many other countries.

A regenerative model that can be applied worldwide

In the United States, one of the most documented cases is that of the Aberdeen Proving Ground in Maryland. The groundwater below this old military-industrial site, where industrial chemicals and chemical arms were stored from 1940 until the 1970s, is heavily polluted. Phyto-remediation with white poplars uses the capacity of these trees to absorb and degrade the toxins through their roots and enzymatic processes. The pollutants should be reduced by 85% in 30 years using such natural methods.
In Spain, the European project Phy2Climate has developed an initiative in Tarragona to decontaminate soil affected by hydrocarbons by planting species that will later be used for biofuel production. It also has projects in Serbia, Lithuania and Argentina. The holistic focus combines environmental clean-up with sustainable energy generation.
In Germany, a North Duisburg Country Park project has transformed an old industrial plant into a public park, where vegetation helps restore polluted land, in this way incorporating industrial history with ecological regeneration.
In Bolivia, a young Aymara called Dayana Blanco is leading the Uru Uru Team community project started in 2019. The team consists of 70 young people, most of them women, who are restoring Lake Uru Uru using native plants such as southern bulrush (Schoenoplectus californicus). In four years, they’ve planted more than 3,000 of them and built dozens of floating rafts. Thanks to this, the water quality has improved and wildlife has returned to the area, showing how ancestral knowledge combined with modern science can achieve impressively positive results.
In Bangladesh, they have developed and proven phyto-remediation projects with a fern called ladder brake (Pteris vittata) to eliminate arsenic from potable water. It makes use of the natural capacity of the fern to absorb and accumulate the dangerous toxin and is an economic, accessible solution for the country’s rural communities.

Urban applications of phyto-remediation

Phyto-remediation offers many benefits, both sustainable and economic. Beyond the ecological impact, the strategy also seeks to boost fishing and sustainable tourism, and promote community participation.

It is a low-cost, less-invasive technique than other decontamination methods and helps to improve local biodiversity. But it also presents challenges, such as the need for time for the plants grow and absorb the pollutants, and is limited to certain types of chemical compounds and environmental conditions.

As well as its application to natural areas, the use of phyto-remediation is being incorporated into urban environments. One of the most interesting cases is the Malaga Urban Forest project that seeks to transform old industrial sites into a big green space by planting indigenous species that also help decontaminate the soils. It consists of a citizen initiative that began to transform old industrial land into a 177,000-square-meter Mediterranean forest. One of the project’s main challenges is the decontamination of the land, which contains high concentrations of hydrocarbons both at soil and groundwater level due to its industrial past. The vegetation is working hard to eliminate them.

In Algeciras, the NICE wetland park is also supported by sustainable water management through natural, vegetation-based filtering systems. Located next to Torre Almirante secondary school, the park treats rainwater and wastewater from the school washrooms in a two-stage process: first, a physical filtering system using sand and gravel, followed by biological treatment using aquatic plants.

Benefits, challenges and the future of phyto-remediation

Phyto-remediation is the successful convergence of technology, ecology and community participation. As more towns, cities and communities go about adopting this measure, it opens the possibility of transforming degraded spaces into healthy, vibrant environments.

In a global context, where environmental challenges are increasingly more visible, this kind of solution represents a path toward re-greening, regeneration and hope, demonstrating that, often, the most effective responses to our problems are close at hand: coming directly from nature itself.

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