KINETIC REGULARITIES OF LIGNIN MODEL COMPOUNDS OZONOLYSIS

摘要

Recently, ozonolysis of aqueous solutions, containing lignin derivatives, has attracted increasing attention in connection with the development of new technologies of wastewater purification in the pulp and paper industry. Use of ozone to reduce the level of phenolic compounds in industrial wastewater appears to be a promising technology due to high reactivity of ozone with ethylene and aromatic bonds, its high oxidative power and non-pollutant nature. Lignin is a natural phenolic polymer. The structure of lignin molecule is very complicated thus kinetics and mechanism of lignin ozonolysis are studied using model phenolic compounds. The reaction of phenolic compounds decomposition includes many stages and passes through the formation of muconic acid, quinones, maleic and fumaric acid. The final product is usually oxalic acid. The purpose of our study was to compare the reactivity of some lignin model compounds with ozone. A number of compounds such as phenol, catecol, guaiacol (o-methoxyphenol), siringol (2,6-dimethoxyphenol), vanillin (4-hydroxy-3- methoxybenzaldehyde) and ferulic acid (3-(4-hydroxy-3-methoxyphenyl) prop-2-enoic acid) were investigated.