In this PhD thesis, using reactive azo dyes as model components, several aspects were studied contributing to a better understanding of dye degradation and its removal from textile wastewater. A number of available molecular tools were implemented and evaluated to assess the microbial community composition and some important gene functions in activated sludge from (textile) Wastewater Treatment Plants (WWTPs). The study also includes the analysis of the microbial community in activated sludge from well-operating textile WWTPs in comparison with municipal WWTPs over two seasons (winter and summer), and to explain observed differences by environmental variables.
The study developed and evaluated a combined method of partial Fenton oxidation and biological treatment using activated sludge for decolorization of azo dyes. Using RV5 as a model dye, color removal was significantly higher when the combined Fenton treatment/activated sludge method was used, as opposed to separate application of these treatment technologies.
A list of bacterial strains capable of decolorizing and/or degrading azo dyes commonly applied in textile production (monoazo dye Reactive Orange 16 and diazo dye Reactive Green 19) were isolated and characterized from activated sludge systems used in the treatment of (textile) wastewater are listed. These strains offer promising perspectives on a practical level, which requires a stable enzymatic performance of the isolates during the different phases of the purification cycle (thermotolerant).
Read More: Decolorization of textile waste water, with an emphasis on microbial treatment processes
