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Phytotechnology seeks to remedy damage from mining

Phytotechnology seeks to remedy damage from mining

Now, thanks to a new scientific innovation project, mining could go from being an activity highly resisted by environmentalists to becoming a sustainable industry in at least some of its production processes. This is a phytotechnology project created by Dr. Claudia Ortiz, a biochemist at the University of Santiago. Using endemic plants, she and her team of researchers seek to treat, stabilize and remediate soils and waters impacted by industrial activities, a process called "phytoremediation." "These technologies generate a relevant environmental contribution since they allow progress towards industrial development in a sustainable way and, at the same time, contribute in social matters because they allow facing the unwanted effects of production processes involving the community," explained the Chilean scientist in an interview with Tierramérica. "We want to become a world benchmark for this type of innovative environmental solutions," he added. Phytotechnologies are based on the use of endemic plants and microorganisms, which are selected for their acclimatization process in economically exploited environments. In Chile, some of the plants used are of the genus baccharis, atriplex and the naturalized phragmites australis. Ortiz's research emerged in the early 2000s and initially aimed to determine the reason why there are some plant species that have the ability to grow in certain conditions associated with poor soil quality, for example.

"We focused on the issue of tolerance to metals and from there a line emerged that allowed us to determine that there are some plant species and microorganisms that had certain capacities to tolerate the conditions and at the same time improve the substrates or sites that they were shocked, "he said. In other words, he added, it started from basic research that eventually became applied research with a specific use. "In the demonstrations we have done in the field, we determined that there is an improvement in the amount of organic matter in some substrates that are chemically inert, that do not intervene in the absorption and fixation of nutrients," he explained. In this case, he said, "the improvement ranges from zero to five percent, or from zero to one percent, depending on how long the plants are incorporated into the system." "There are improvements in the physical and chemical properties of the places where the plants are installed, and that is thanks to the contribution of microorganisms and plants that have the ability to release some beneficial compounds for the environment," he added. The technology developed by the scientist is also applied to water treatment, where plants are capable of capturing metallic elements such as copper, mobilizing it in the roots. "Bacteria can decrease sulfate content by as much as 30 percent from a liquid waste that has high concentrations of sulfate," he said. So far, the pilots carried out by Ortiz and his team have been applied exclusively on tailings substrate. However, in the experience through the nursery laboratory they have also been done in mixtures of different types of substrate. "On the issue of water, we have worked in clear waters, which are from the tailings dams, but today we are also doing experiments on the ground, with leachate of water from landfills where garbage is deposited," he said. The technology developed by the academic is already applied in Chile, particularly in some sites of the state-owned Corporación del Cobre de Chile (Codelco) and the National Mining Company. It is also in the validation stage in Bolivia, Colombia and Canada. The preliminary results obtained with the pilot implementation of the system "are very encouraging," Sergio Molina, the manager of Sustainability and External Affairs for Codelco's Chuquicamata Division, told Tierramérica.

"Codelco is particularly concerned about permanently incorporating new technologies that aim to minimize the impacts caused on the environment," said the manager of the Chuquicamata mine, the largest open pit mine in the world and the largest copper producer in the country. "Hence, we have generated alliances with study houses, such as the University of Santiago, to develop pilot projects that go in that direction and with which we have achieved excellent results," he concluded.

Engineer Lucio Cuenca, director of the Latin American Observatory of Environmental Conflicts, warned Tierramérica that the technology developed by Ortiz addresses a segment of the extractive process, but does not solve all the environmental problems generated by mining. "What it does is replace some chemical substances like sulfuric acid, but it does not solve, for example, the high amounts of water that are extracted in the mining process," he said.

It is estimated that copper extraction uses more than 12,000 liters per second of water, while international organizations confirm a considerable drop in the availability of surface water in this South American country. Mining is a fundamental sector of the local economy. In 2013 it contributed 11.1 percent of the gross domestic product, its exports totaled 45,273.6 million dollars, while it generates almost one million direct or indirect jobs.

Chile is the world's largest copper producer and exporter and also extracts molybdenum and, to a lesser extent, gold, silver and iron. The truth is that the investigations of Ortiz and his team continue, now in the field of desalination of marine waters, through biofilter systems, an encouraging alternative for the mining industry.

In a first stage “we are treating waters with high levels of chloride that are associated with other elements such as ions, which are also associated with saline waters.

"We work with halophyte plant species, that is, they are very tolerant to high salinity and are very good at capturing and sucking these salts and store them in their tissues," explained the biochemist.

"We have been experimenting and we have had enough good results to be able to apply it specifically to leachate from landfills," he added.

In parallel, the research team develops two projects sponsored by the Chilean State Development Corporation: one of them with seaweed matrices and the other with nanotechnology, to eliminate the particularly saline elements found in seawater or waters with a high concentration of you go out.

“We are aiming for this technology to be used for the use of seawater in mining processes.

We have determined that under certain conditions where seawater is diluted, we could work with matrices that are much cheaper than those used today for desalination ”, he explained.

“These projects are still in development with very promising results and will end next year.

Therefore, we will be able to make a technological offer with another type of matrix ”, he concluded.

This article was originally published by Tierramérica's Latin American newspaper network.

Edited by Estrella Gutiérrez

Ecoportal.net IPS

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Video: Improved Phytoremediation of Heavy Metal Pollution by Dr. Leung (June 2021).