A chemometric approach to understanding the bioelimination of anionic, water-soluble dyes by a biomass - Part 3: Direct dyes

Using a new, rapid and robust laboratory method for assessing the bioelimin ation of water-soluble dyes, the level of bioelimination of a series of dir ect dyes has been determined and a chemometric analysis has been conducted on the bioelimination results to correlate bioelimination with chemical str ucture. Bioelimination varies from 0 to 95% and correlates, for the majorit y of the direct dyes studied, with their size/charge ratio. The bioeliminat ion of direct dyes is enhanced by large size/charge ratios, the presence of aromatic amino functions and extended azo (naphthalene) chromophores.