In Chile, various bodies of water, such as the Mapocho River, receive agricultural and industrial waste, including organochlorine pesticides, chemical compounds used for pest control but which accumulate in the environment and affect health and biodiversity.
Despite the toxicity of these compounds, they are not regulated in the country due to the lack of data confirming their presence. This situation has created a critical gap between the need to control pollution and the actual tools available to do so, especially in agricultural areas, where irrigation water is key to food production.
Current technologies for analyzing these contaminants often require expensive materials, as well as the use of other toxic solvents and processes that can generate polluting waste. In this scenario, the development of more sustainable alternatives developed in the laboratory becomes urgent.
Dr. Carla Toledo, a researcher at Usach’s Faculty of Chemistry and Biology, spearheads a Fondecyt Regular project aimed at tackling water pollution through sustainable innovation. Her project focuses on creating biodegradable materials for contaminant detection, adhering to the core tenets of green chemistry—including cleaner methodologies, minimized toxic solvent usage, and reduced waste generation.
“Our goal is to develop far more environmentally friendly analytical methods, reducing waste and eliminating the use of toxic solvents,” the researcher explains. “We aim to apply these methods to contaminants like organochlorines, which are currently unregulated in Chile often because their presence isn’t even known.”
Focusing on the use of plants like loofah—popularly recognized as a vegetable sponge—the project aims to create novel materials designed to absorb contaminants from water.
These plants have cellulosic and porous structures, which allow them to act as natural filters in two ways: one, by combining them with deep hydrophobic eutectic solvents (HDES), known as “green solvents” because they are less toxic and more sustainable; and two, by subjecting them to a pyrolysis process, which converts them into carbon fibers with a high capacity to trap toxic substances. These materials are then applied in advanced analysis techniques, such as gas chromatography with electron capture detection (GC-ECD), which allows pesticides to be identified in water samples taken from the Mapocho River, even when present in very low concentrations.
“The interesting thing is that these materials, in addition to being inexpensive and easy to obtain, could have applications beyond the laboratory. In the future, they could be transformed into reusable filters for communities that currently do not have access to water treatment technologies,” says Dr. Toledo.
The application of plant materials as biosorbents not only ensures efficient analysis but also presents a highly accessible and ecologically sound solution. In stark contrast to conventional synthetic materials—which demand complex production, rely on organic solvents, and are frequently discarded after a single use—loofah sponges emerge as a superior, reusable, biodegradable, and easily obtainable alternative.
This approach is particularly relevant considering that many agricultural areas depend on water sources such as the Mapocho River, which are exposed to a pollutant load that is difficult to measure with current methods. By integrating sustainable materials into advanced detection methodologies, the project seeks to reduce the gap between scientific knowledge and its application in the field, with a view to promoting new environmental monitoring policies and equitable access to sanitation technologies.
“The goal is for this solution to evolve beyond simple laboratory pollutant detection, becoming practically implementable on a larger scale,” the researcher clarifies. “We are currently assessing materials that offer high efficiency, alongside being replicable, reusable, and designed for minimal waste, thus actively preventing further environmental burden.”
The project is expected to run for four years, during which different experimental stages will be addressed. During the first years, the team will focus on characterizing the biomaterials and functionalizing them with green solvents, while in the following years, they will move toward transforming them into carbon fibers through pyrolysis. Each phase involves the development of specific analytical methodologies to validate their efficiency in detecting organochlorine pesticides present in natural waters.
“Our goal is that, by the end of the project, we will have validated methodologies that are efficient, low-cost, and aligned with the principles of green chemistry. It is not just about innovating in the laboratory but doing so with environmental awareness and thinking about its real applicability,” concludes Dr. Toledo.