ABSTRACT
Molecular oxygen requires four electrons for its complete reduction to water. One, two, and three electron-reduced intermediates are possible. These are superoxide, hydrogen peroxide, and hydroxyl radical, respectively, with the later being the most toxic and reactive. While hydrogen peroxide (H2O2) is the least reactive of the reduced-oxygen species, it persists longer and may react to form the hydroxyl radical. Representative profiles of H2O2 concentration showed some striking contrasts and provided more detailed information than the temperature values. While it is well known that dissolved organic carbon is related to production of H2O2 in quartz tubes, the areal production of H2O2 is the same in lakes of different dissolved organic carbon concentration. In colored lakes, the production rate is higher at the surface, but the extinction coefficient is much steeper making the integrated production similar. Since production occurs during the day and decay occurs during both daytime and nighttime periods, a dynamic steady state exists for temperate latitudes.
