FOURIER-TRANSFORM RAMAN-SPECTROSCOPIC STUDIES OF A NOVEL WOOD PULP BLEACHING SYSTEM

The use of near-infrared (NIR) Fourier transform (FT) Raman spectrosco py for the study of lignocellulosic materials is discussed. An applica tion utilizing NIR FT-Raman spectroscopy to study a novel chlorine-fre e process for the bleaching of wood pulps is presented in detail. The new process, still under development, entails the oxidation of residua l lignin in wood pulps by vanadium-substituted polyoxometalates, and r eoxidation of the reduced polyoxometalates by chlorine-free oxidants s uch as air, dioxygen, peroxides or ozone. Results from FT-Raman measur ements of polyoxometalate-treated pulps are compared with those from c hemical, spectroscopic and optical techniques commonly used in the pul p and paper industry.