Abstract:
The study of discoloration of lignin solution by ozone in horizontal pipe was carried out in this research. It was found that, at the early state of ozonation, color of lignin solution increased as a result of quinonial structure formation by Darkin reaction. When the quinine was further oxidized, the color became decreased. COD of solution, on the other hand, was found to decrease progressively with time confirming the continual degradation of lignin molecules. It was also found than the lignin color functional groups were sensitive to ozonation and, thus, a direct proportionality of the amount of color removed on lignin concentration was observed. In addition, the efficiency of lignin solution discoloration was largely affected by interphase mass transfer which was governed by the intense of mixing and the extent of interfacial area. Consequently, in order to achieve higher lignin discoloration efficiency and application of static mixer is considered essential.