People are looting the periodic table while turning a blind eye to the risks of doing so, researchers say

People are looting the periodic table while turning a blind eye to the risks of doing so, researchers say

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For millions of years, nature has practically made do with only a few elements in the periodic table. Carbon, calcium, oxygen, hydrogen, nitrogen, phosphorus, silicon, sulfur, magnesium and potassium are the building blocks of almost all life on our planet (tree trunks, leaves, hair, teeth, etc.). However, building people’s worlds—including cities, health care products, railroads, airplanes and their engines, computers, smartphones, and more—requires more chemical elements.

A recent article published in Trends in Ecology and Evolution and written by researchers from CREAF, the Universitat Autònoma de Barcelona (UAB) and the Spanish National Research Council (CSIC), warns that the range of chemical elements needed by humans (something scientifically known as the human elementome) deviates from what in more and more of what nature has. requires (the biological element).

In 1900, about 80% of the elements used by humans came from biomass (wood, plants, food, etc.). This figure dropped to 32% by 2005 and is expected to reach around 22% in 2050. We are moving towards a situation where 80% of the elements we use come from non-biological sources.

Non-biological elements are rare or virtually absent in living organisms and rare in general; in many cases, their main reserves are located in only a few countries. They must be obtained from geological sources, which involve extraction, trade between countries and the development of efficient recycling technologies, while their scarcity and location create the potential for social, economic, geopolitical and environmental conflict.

Thus, what might initially appear to be a purely scientific problem actually has much wider ramifications. “Sustaining the human element will be increasingly complicated and risky; it will have to be done from the point of view of environmental justice and, of course, with a more rational use of the Earth’s limited resources”, sums up Jaume Terradas, CREAF founder. , honorary professor at UAB and one of the three authors of the article.

Humanity, closely related to the extensive use of the periodic table

The study examines human history in relation to its use of the elements of the periodic table. “Humans have moved from using common materials such as clay, stone and lime, the elements of which are constantly recycled in the earth, in nature and in the atmosphere, to using many other elements, especially those known as rare earths. “, says Jordi Sardans, CREAF researcher and co-author of the study. According to the article, the human and biological elements began to diverge in the decade of the 1900s as a result of the continued increase in the use of non-biomass materials (fossil fuels, metal/industrial materials, and building materials).

In 1900, 79% of all materials used by humans annually were biomass materials, up from 32% in 2005, and 22% currently estimated for 2050. Elements used in construction, transportation, industry and, more recently, new technologies , such as computing and photovoltaic devices and mobile phones, were added to the human element throughout the 20th century.

These include silicon, nickel, copper, chromium, and gold, as well as others that are less common, such as samarium, ytterbium, yttrium, and neodymium. In the last two decades, there has been an increase in the use of such rare elements, due to the implementation and expansion of new technologies and clean energy sources.

“The consumption/extraction of mineral elements is increasing at a rate of about 3% per year, and this will continue until 2050,” says Josep Peñuelas, CREAF and CSIC researcher and the other co-author of the study. “In this scenario, we may have exhausted all reserves of some of these elements (gold and antimony) by 2050 and of others (molybdenum and zinc) within a hundred years.”

Environmental, economic, social and geopolitical risks

The article leaves no room for doubt: the extraction of Earth’s chemical elements could be a limiting factor and lead to crises at every level. Using more elements in the periodic table involves extracting more minerals, increasing energy consumption and associated CO.2 emissions. In addition, the increasing scarcity of the elements in question poses a threat to their availability, especially for poorer countries, and makes it difficult for even rich countries to maintain production, thus affecting economic development.

Against this background, there are also important and problematic geopolitical considerations. Natural reserves of some elements, including rare earth elements, are located in a limited number of countries (China, Vietnam, Brazil, USA, Russia and the Democratic Republic of Congo); China actually controls over 90% of global supply and almost 40% of reserves. Their availability is therefore subject to supply and price fluctuations caused by opposing geopolitical interests, with the risk of conflict.

Out with programmed wear, with recycling and recovery

The authors emphasize the need to end planned obsolescence (the policy of planning or designing a product to have an artificially limited useful life), as well as to develop new technologies that contribute to a more profitable use of rare elements and enable recycling and their widespread and efficient reuse.

Currently, there are few – if any – alternatives to many such elements, and their recycling rates are low because they are used in small quantities in combination with other materials in a wide range of products. Current recovery techniques have poor efficiency levels and pose a high risk of pollution due to the toxicity of rare earth elements.

The article mentions various technologies that could be used to recover rare elements. One is bioleaching, the extraction of metals from their ores by using living organisms such as bacteria, which can accumulate rare earth elements if they come into contact with industrial waste.

Meanwhile, to avoid pollution, scientists are studying biosorption, a physicochemical process that occurs naturally in certain organisms and allows them to filter pollutants, such as heavy metals, in wastewater.

Other possibilities include cryomylation, where recovery occurs by electrochemical deposition; the use of various carbon-based nanomaterials as sorption media to preconcentrate rare earth elements from dissolved solids in wastewater; hydrometallurgy for the substantial recovery of rare earth elements and heavy metals from apatite and various scraps; and pyrometallurgy, or CO extraction of supercritical fluids2.

In any case, the development of new ways of producing and recycling these elements on a large scale is essential.

More information:
Josep Penuelas et al, Increasing divergence between human and biological elements, Trends in Ecology and Evolution (2022). DOI: 10.1016/j.tree.2022.08.007

Provided by the University of Barcelona

Citation: Humans plunder periodic table while turning a blind eye to risks of doing so, researchers say (2023, January 17) Retrieved January 17, 2023, from -periodical- table-eye.html

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