Photoinduzierte hydroxylierungsreaktionen organischer chemikalien in natürlichen Gewässern - Nitrate als potentielle OH-radikalquellen -.

Organic chemicals are concentrated in natural waters, where they undergo complex reactions under the influence of solar radiation and catalyzed by substances such as humic acid as well as nitrate and nitrite salts. Nitrates are present in high concentrations in natural waters (5 - 50 mg/l). The photolysis of the nitrate ion leads to the formation of OH-radicals. In this investigation the steady-state concentration of OH-radicals in different aquatic environments is estimated (∼ 5 · 10-16 mol/l). It depends on the amount of nitrate dissolved in the water. Under the conditions of this work the half life for a great number of organic chemicals lies in the range 80 - 400 hours (for the reaction with OH-radicals)