Decolorization and Degradation of azo dyes in textile wastewater effluent by Aspergillus Niger and Aspergillus ochraceous

Abstract

In this study, fungi were isolated from contaminated soil collected from textile wool factories in Thi Qar Governorate. The results showed a high potential for removing Methylene Blue dye by Aspergillus niger and Aspergillus ochraceous. The removal process was conducted under optimized conditions, including different concentrations of the azo dye, pH levels, carbon sources, and nitrogen sources. The results indicated that the fungi Aspergillus niger and Aspergillus. Ochraceus were the most common isolates. Both fungi were treated with Methylene Blue dye in solid and liquid media, and both showed the ability to degrade this dye. However, Aspergillus niger demonstrated higher activity in color removal compared to Aspergillus ochraceous, with a diameter of (9) cm in solid medium for Aspergillus niger and (8) cm for Aspergillus. ochraceus. These results were confirmed by statistical analysis, which showed significant differences between these fungi and concentrations. The decolorization percentage was confirmed by Fourier Transform Infrared (FTIR) spectroscopy of which showed complete disappearance of peaks at 500 nm and at 1500 nm, indicates the degradation of dyes due to fungal activity, The technology also confirmed that a pH of 7 was the optimal pH for dye biodegradation compared to pH 4. This was observed through the dry weight of the fungi, with Aspergillus niger reaching to (2.35) and Aspergillus ochraceous reaching to (2.15) at pH 7. Also, in pH 4, the dry weight of Aspergillus niger and Aspergillus. ochraceus reached (2.17) and (2.05) respectively. Furthermore, the study confirmed the potential use of filamentous fungi in treating dye-contaminated water, regardless of their pH values.