CHARACTERISTICS OF CHROMOPHORIC DISSOLVED MATTERS IN BLEACHING EFFLUENT

Because reports on the characteristics of the chromophoric dissolved matters (CDM) which result in the undesired color of the bleaching effluent are limited and inconclusive, solid phase extraction (SPE), UV/Visible spectroscopy (UV/Vis), gel permeation chromatography (GPC), ultrafiltration (UF), and GC/MS were used to get an comprehensive understanding of the CDM. SPE using granular active carbon as adsorbent was proved effective in extracting CDM from the bleaching effluent. UV/Vis analyses showed that CDM were mainly unsaturated compounds, possibly aromatics. The analysis of the molecular weight distribution by GPC indicated that 90% of CDM was less than 1100Da. The results of UF indicated that 12% of the color was caused by chromophoric dissolved matters in low molecular weight range (LCDM). GC/MS analysis showed that LCDM was mainly the organochlorides, aromatics and polycyclic aromatic hydrocarbons.