Potential of combined fungal and bacterial treatment for color removal in textile wastewater

Low efficiency of dye removal by mixed bacterial communities and high rates of dye decolorization by white-rot fungi suggest a combination of both processes to be an option of treatment of textile wastewaters containing dyes and high concentrations of organics. Bacteria were able to remove mono-azo dye but not other chemically different dyes whereas decolorization rates using Irpex lacteus mostly exceeded 90% within less than one week irrespective of dye structure. Decolorization rates for industrial textile wastewaters containing 2–3 different dyes by fungal trickling filters (FTF) attained 91%, 86%, 35% within 5–12 d. Sequential two-step application of FTF and bacterial reactors resulted in efficient decolorization in 1st step (various single dyes, 94–99% within 5 d; wastewater I, 90% within 7 d) and TOC reduction of 95–97% in the two steps. Large potential of combined use of white-rot fungi and traditional bacterial treatment systems for bioremediation of textile wastewaters was demonstrated.