Effect of hot chlorine dioxide delignification on AOX in bagasse pulp wastewater

This work describes the effect of the hot chlorine dioxide delignification (D_HT) on the properties of bagasse fiber and the formation of AOX. The bagasse pulp was subjected to both D_HT and normal temperature chlorine dioxide delignification (D₀), and the AOX contents in the effluent were determined respectively. The GC–MS results showed that the main components of the D₀ stage wastewater were chlorinated hydrocarbons and chlorinated diphenyls. In contrast, those AOXs in the D_HT stage wastewater were very few. The GC–MS, ATR-FTIR, and XPS results showed the D_HT process is more effective in the removal of the residual phenolic lignin and the hemicellulose-linked HexA compared with D₀. Furthermore, in comparison, the AOX content could be reduced by 50% with D_HT. The fully bleached pulp obtained via D_HTE_pD process has a higher brightness than that obtained by D₀E_pD, which provides a reliable theoretical basis for industrial application.