The appearance of free oxygen in the Earth’s atmosphere led to the Great Oxidation Event. This was triggered by cyanobacteria producing the oxygen which developed into multicellular forms as early as ...

Limnology and Oceanography, Vol. 55, No. 3 (May 2010), pp. 1064-1074 (11 pages) We elucidate the controls on the δ¹ɸO values of microbially produced nitrate by tracking the δ¹ɸO of nitrite and nitrate ...

A number of novel concepts to achieve high methane conversion and high selectivity to partial oxidation products will be employed. First, is the use of A+O2/AO system as an oxygen shuttle between O2 ...

Methane emissions are strongly reduced in lakes with anoxic bottom waters. But – contrary to what has previously been assumed – methane removal is not always due to archaea or anaerobic bacteria. A ...

Journal (Water Pollution Control Federation), Vol. 61, No. 8 (Aug., 1989), pp. 1449-1463 (15 pages) Total barrier oxidation ditches (TBODs) have been installed over the past 5 years in the U. S. under ...

It may have been unexpectedly easy for the air to become rich in oxygen. A new simulation of the rise of oxygen suggests that it was driven by the planet itself, and needed little help from living ...