Reactive azo dyes occur in textile dyehouse
wastewater in concentrations ranging from 5 to
1500 mg l1 due to their poor fixation to fabrics
(Pierce, 1994). Moreover, reactive azo dyes are not
degraded by conventional aerobic sewage treatment
plants as they are resistant to biological
oxidative degradation (Easton, 1995). Decolourisation
can be achieved using either anaerobic
digestion, microbial generation of oxygen radicals,
i.e. laccase activity of white-rot fungi (Schliephake
et al., 2000) or expensive physico-chemical treatments
(O’Neill et al., 2000).