Researchers at the Oak Ridge National Laboratory have discovered an adsorbent with high selectivity for chromium and arsenic in real conditions where water resources contain many chemically similar elements.
Chromium and arsenic are byproducts of a number of mining, production and manufacturing processes. Both are toxic and can cause adverse health effects, including cancer. Even low levels pose significant risks to living organisms because doses bioaccumulate, or build up with each exposure, and can gradually reach harmful amounts. In water, these metals dissolve to form chromate and arsenate oxoanions, or salts, that are chemically similar to beneficial minerals that are naturally present in water including phosphate, sulphate, nitrate and bicarbonate. Chromate and arsenate are highly mobile in water and can have far-reaching impacts. They do not degrade and are permanent in the environment without intervention. Targeted approaches are needed to separate these metals from harmless mineral salts that are vital to the ecosystem.
This is where adsorbents come in. Adsorbents are materials that are designed to target specific elements and bind them to a surface. They have broad applications in helping to recover precious metals or remove pollutants from the environment. In a paper published in the journal Small, the Oak Ridge scientists explain that the new adsorbent they discovered captures chromium and arsenic in a balanced 2-to-1 ratio. The fundamental advance creates synergy between chromium and arsenic capture so that the more chromium the material grabs, the more arsenic it can also remove. “It is rare for an adsorbent to capture two pollutants simultaneously, and to work quickly and efficiently in realistic scenarios to address the broad range of water conditions worldwide,” Santa Jansone-Popova, co-author of the study, said in a media statement.
Source: This news is originally published by mining