An often-overlooked form of manganese, an element critical to many life processes, is far more prevalent in ocean environments than previously known, according to a study led by University of Delaware researchers that was published this week in Science.
The discovery alters understanding of the chemistry that moves manganese and other elements, like oxygen and carbon, through the natural world. Manganese is an essential nutrient for most organisms and helps plants produce oxygen during photosynthesis.
“You wouldn’t think manganese is that important, but without manganese, we wouldn’t have the molecular oxygen that we breathe,” said study co-author George Luther, Maxwell P. and Mildred H. Harrington Professor of Oceanography in the School of Marine Science and Policy within UD’s College of Earth, Ocean, and Environment.
Manganese is present in the environment in three forms—manganese(II), manganese(III) and manganese(IV)—the difference related to the oxidation state, or number of electrons present. When elements lose or gain an electron, the oxidation state changes in a “redox reaction,” like when iron turns into rust by losing electrons to oxygen in air.
The second-most common metal in the earth’s crust, manganese rapidly changes between oxidation states while reacting with other elements in the environment.
Traditionally, manganese(II) and manganese(IV) were believed to be the dominant forms in aquatic environments. But in the mid-2000s, Luther found in a surprising result that manganese(III) was also present in a Black Sea “transition zone,” an area where oxygen levels are relatively high near the surface but gradually diminish deeper down in the water.
Read more at: Phys.org