PERIFERIA
A method using seaweed to remove arsenic from water has been developed in Chile.
Jan 14, 2026
The research, led by Dr. Loretto Contreras, proposes the use of biochar obtained from brown algae to remove arsenic naturally present in some areas of the country.
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A new method based on biochar derived from seaweed could become a sustainable alternative to combat arsenic contamination in freshwater sources intended for human consumption, a little-known problem affecting some areas of the country.
The innovation was submitted as a patent application to the Chilean National Institute of Industrial Property (INAPI) by Loretto Contreras Porcia, director of the Laboratory of Ecology and Molecular Biology in Algae (LEBMA) at Andrés Bello University (UNAB) and a researcher at the Quintay Marine Research Center (CIMARQ UNAB) and the Millennium Institute SECOS. She proposes a technological solution focused on the circular economy and public health.
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The invention—registered in December 2025—describes a method for adsorbing arsenic from freshwater using biochar obtained from Macrocystis pyrifera, a brown alga abundant on the Chilean coast, activated with ferric chloride (FeClâ‚‚). The patent protects both the activated biochar and its production process, as well as its application in arsenic adsorption systems, with the aim of generating safe drinking water.
This development is particularly relevant considering the persistence of this contaminant in various regions of Chile, primarily associated with natural geological conditions.
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The risk of volcanic zones
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According to a World Bank report published in 2019, between 2011 and 2018, arsenic levels equal to or exceeding the threshold of 0.01 mg/L—the maximum value recommended by the World Health Organization (WHO) for drinking water—were recorded in 83 of the 392 locations evaluated in the country. “Much of the volcanic zone of northern Chile, in particular, had access to drinking water contaminated with arsenic until 2017,” explains Dr. Contreras. One of the areas studied is the Altiplano-Puna region, where research has shown that the distribution of arsenic is strongly influenced by the tectonic environment and intense volcanic activity. In these areas, volcanoes act as emission points that allow arsenic released from the Earth's crust to reach the surface, from where it can migrate downhill through groundwater and surface water, such as rivers, streams, and creeks.
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