REACTION RATE CHARACTERISTICS OF HEXAVALENT CHROMIUM REMOVAL USING ZEROVALENT IRON AND BOF/EAF SLAG

摘要

According to the present invention, hexavalent chromium is a toxic substance that has a very high solubility and mobility, and has biological toxicity and carcinogenicity, which require appropriate treatment. The present research is conducted to derive the correlation between factors affecting on a hexavalent chromium reduction reaction and a reduction reaction constant, in order to optimize a hexavalent chromium removal process using zerovalent iron as a catalyst, which overcomes the disadvantages of the existing expensive ion exchange method or the neutralization precipitating method with large sludge generation. In addition, the correlation between the effects of a particle size of zero-valent iron, an injection amount, an initial pH condition, and an addition of slag, on a hexavalent chromium removal reaction, and a reduction reaction constant of hexavalent chromium is investigated, and a physical chemical change on a surface of a zero-valent iron catalyst before and after the reduction reaction of hexavalent chromium is observed through an FE-SEM and EDS analysis. When the particle size and the injection amount are different in the hexavalent chromium removal experiment, the specific surface area and the reduction reaction constant k value according to the injection amount was linearly proportional to the particle size and the injection amount, and when the initial pH condition is varied, the hexavalent chromium removal reaction rate of the zerovalent at pH 5 or higher is significantly reduced.;COPYRIGHT KIPO 2018