Formation of the Oxidation Products in the Ozonation of Wood with Different Moisture Contents

The absorption of ozone by aspen wood with moisture contents of 45, 55, and 70% is studied. Time dependencies are obtained for the specific absorption of ozone, the degree of ozone conversion, and the content of the products of oxidation. It is shown that the resulting compounds are products of the oxidative degradation of lignin, and that the efficiency of delignification is greatest for wood with a moisture content of 55%. Water-soluble products are analyzed via HPLC, revealing the presence of oxalic, formic, and glyoxylic acids in contact solutions. Based on the dependence of the content of acids on the specific consumption of ozone, it is concluded that the acids are oxidized by ozone. The inhibiting role of the reactions between ozone and water-dissolved products of the substrate oxidation is noted.