MURTADHA ABDULZAHRA MAKHRIB AND RANA HADI HAMEED AL-SHAMMARI*
Biology Department, College of Science, Mustansiriyah University, Baghdad, Iraq
*(e-mail: dr.rana@uomustansiriyah.edu.iq; Mobile : 00964 79022 57121)
(Received: July 5, 2022; Accepted: August 12, 2022)
ABSTRACT
As dyes are frequently discharged into wastewaters and dyes are extensively used in the textile industry
so it’s necessary to find out an efficient and eco-friendly methods for treating wastewaters resulting
from industrial pollutions. Five fungal species were isolated from polluted soil two from them were able
to absorb azo dyes and Aspergillus terreus was the most effective species to remove 90% of dye after 48
h. Dye removal was investigated in 500 mg/l concentration of Azo dyes at initial pH 5.5 and 2.0 g fresh
wet of fungal pellets was kept in rotary shakers at 160 rpm/min at 25°C. Fourier transform infrared
spectroscopy, the decolorization analysis of the biodegraded Congo red solution was achieved by the
change in the absorption spectrum in the wavelength 495 nm and scanning electron microscopy analysis
revealed that dye removal was dependent on hydroxyl and amine groups in the cell wall polymers. The
cleavage of Congo red bond was confirmed through HPLC assay, the absorbance at the retention time of
1.97 min was recorded for the Congo red dye, where 100% concentration of the dye was eluted in
aqueous solution after treatment showed no absorbance at the same retention time. A. terreus is highly
capable of sorption azo dyes and could be employed to remove dyes in industrial wastewater.
Key words : Azo dye, filamentous fungi, immobilization