Summary: | The white-rot fungus Irpex lacteus is able to decolorize a wide range of synthetic textile dyes. The aim of this study was a verification of this capability when the decolorization takes place in a medium without addition of an easily degradable carbon source, such as glucose. The decolorization ability was verified by degradation of the azo dye Reactive Orange 16 (RO16) in a laboratory scale Rotating Drum Biological Contactor (RDBC). The drum was filled by a mixture of straw (source of nutrients) and Al-Schwimmbett® plastic particles. Two sets of batch decolorization experiments with synthetic wastewater consisting of tap water and dye RO16 (initial concentration 100 mg.dm-3) were performed. A decrease of the degradation rate of the dye RO16 in subsequent sets of batch degradation experiments was observed. In the continuous experiments with the tap water based medium (input RO16 concentration 50 mg dm-3) the decolorization efficiency was very low – less than 20 % within 15 days. When glucose was added to the input stream (at concentration of 5 g dm-3), high degradation efficiency was observed – more than 95 % on 14th day. Besides the higher dye degradation rate, the other impact of the glucose addition to the medium was the overgrowing of the fungal biofilm. It resulted in a significant decrease of liquid volume in the reactor and certain operational problems, such as clogging of the liquid output with the biomass.
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