The University of Massachusetts Amherst
University of Massachusetts Amherst

Search Google Appliance

Links

Oxidation of iron and manganese by ozone

TitleOxidation of iron and manganese by ozone
Publication TypeJournal Article
Year of Publication1991
AuthorsReckhow DA, Knocke WR, Kearney MJ, Parks CA
JournalOzone: Science & Engineering: The Journal of the International Ozone Association
Volume13
Issue6
Start Page675
Pagination675-695
Date Published06/1991
KeywordsEffects of Bicarbonate Ion, Effects of Organic Matter, Iron Oxidation, Manganese Oxidation, Ozone
Abstract

The oxidation of iron and manganese by ozone was studied in the laboratory. Model waters both with and without organic matter were used. Results showed iron to be very rapidly oxidized to an insoluble form in the absence of organic matter. However, in the presence of organic matter the iron was protected from oxidation by ozone and precipitation. The degree to which this occurred depended on the nature of the organic matter and the chemical environment at the time of mixing the iron stock and the dissolved organic matter.

Experiments with manganese allowed the determination of second order rate constants for the reaction of ozone with manganese at various pH values. The oxidation of manganese in the presence of organic matter occurred in competition with oxidation of the organic matter. As a result, high ozone doses were required to achieve the same degree of removal of manganese. An increase in bicarbonate alkalinity from 50 mg/L to 200 mg/L did not result in an acceleration of the manganese oxidation in the absence of organic matter. However, in the presence of organic matter, higher levels of bicarbonate created conditions that resulted in more complete oxidation of the manganese following total consumption of the dosed ozone.

URLhttp://dx.doi.org/10.1080/01919512.1991.10555708
DOI10.1080/01919512.1991.10555708