Professor Stephan Pflugmacher Lima – Plants could clean up our water
With the Green Liver method, we can purify almost any water. But even more helpful would be to prevent the pollution of our aquatic ecosystems beforehand.

Making a substantial and sustainable contribution to society with a fundamental impact is a goal most researchers can only dream about. But it is something that Stephan Pflugmacher Lima, recently appointed professor of Aquatic Ecotoxicology in an Urban Environment at the University of Helsinki, has achieved. After the successful execution of his project to clean wastewater from an aquaculture farm in Brazil, the legislation was changed to force farmers report on the quantity and kind of wastewater they are disposing into the environment. Hopefully setting up threshold levels in the near future. A small change to the regional legislation of the world’s eighth biggest economy.

“I’m very happy about that small success”, says Pflugmacher Lima modestly.

The protection and purification of freshwater is at the core of Pflugmacher Lima’s expertise. His primary method is what he calls the “Green Liver”. It is a system in which water is purified with the help of native aquatic plants. At the moment Pflugmacher Lima and his colleagues are expanding the concept also to aquatic fungi, by using their ecosystem service in removal.

“We can do a tremendous amount by harnessing the power of the ecosystem”, says Pflugmacher Lima.

“If we use them correctly, aquatic plants can serve as tools. No plant can solve all of our problems, but for almost every problem, there is a plant or a combination of plants that can help”.

The Green Liver is a system where plants are used somewhat as “tools”. There are already numerous aquatic plants laying in the “tool box”, tested as suitable to be employed for different remediation requirements, which under the right conditions can be used to fix various environmental problems related to water quality, in example from eutrophication to toxins removal.

For example in Brazil, the biggest problem with fish farming was that veterinary pharmaceuticals used to treat the fish would make their way into natural lakes and streams. Pflugmacher Lima solved the problem by installing a Green Liver Systems to purify these compounds from the aquacultural effluent before it was released to the nearby reservoir.

“The farmers benefitted by selling their products as more eco-friendly, but nature benefitted as well”, points out Pflugmacher Lima.

Pflugmacher Lima’s great goal is to facilitate mutually beneficial cooperation. He says that water cannot be protected without the help of science, industry, and government working together.

“With the Green Liver method, we can purify almost any water. But even more helpful would be to prevent the pollution of our aquatic ecosystems beforehand.”

As an example, the Professor mentions microplastics, which are one of the biggest problems of water protection in the world today.

According to Pflugmacher Lima, it is also possible to use the Green Liver method to collect plastic (nano- and picoplastic) from the water. Larger pieces of plastic can be harvested by nets formed by dense vegetation or even recycled plant material in places where there is a current. Nano- and picoplastics can be collected by using plants which absorb them into their cellular system. After this, the plants can be collected and the plastic harvested.

“But this is not enough. Avoiding a pollution is better than fixing it afterwards. We need to replace traditionally used plastics with biodegradable, or even better with fully compostable ones and restrict the use of unnecessary plastics”, says Pflugmacher Lima.