The decolourisation of 20 selected @entity24740 dyes by granular sludge from an upward-flow anaerobic sludge bed (UASB) reactor was assayed. Complete reduction was found for all @entity24740 dyes tested, generally yielding colourless products. The reactions followed first-order kinetics and reaction rates varied greatly between dyes: half-life times ranged from 1 to about 100 h. The slowest reaction rates were found for reactive dyes with a @entity21750 reactive group. There was no correlation between a dye's half-life time and its molecular weight, indicating that cell penetration was probably not an important factor. Since granular sludge contains @entity41130 , eight dyes were also monitored for direct chemical decolourisation by @entity41130 . All these dyes were reduced chemically albeit at slower rates than in the presence of sludge at comparable @entity41130 levels. Increasing @entity41130 concentrations, even when present in huge excess, stimulated the @entity24740 reduction rate. The results indicate that granular sludge can decolourise a broad spectrum of @entity24740 dye structures due to non-specific extracellular reactions. Reducing agents (e.g., @entity41130 ) in sludge play an important role. The presence of anaerobic biomass is probably beneficial for maintaining the pools of these reduced compounds.

XXXX dye decolourisation by anaerobic granular sludge.

@entity24740 :: ('CHEBI:33835', 'Chemical') :: ['azo'] @entity21750 :: ('CHEBI:38056', 'Chemical') :: ['triazine'] @entity41130 :: ('CHEBI:15138', 'Chemical') :: ['sulphide']
@entity24740 :: (CHEBI:33835,Chemical) :: ['Azo']
