ABSTRACT
Background: Fungi are free-living heterotrophic microorganisms, which absorb nutrients for growth andreproduction. The integrated fixed film activated sludge (IFAS) system is a beneficial technology for developingconventional activated sludge plants, which consisted of a wide range of microorganisms. Methods: Twelvewastewater samples were collected from four IFAS sites during 3 days. The samples were prepared for count andidentification. The genera of fungi were identified by macroscopic and microscopic features. The physicalchemical analyses were done according to the standard method protocols. To prevent and reduce the growth ofbacteria, 0.05 g/l of chloramphenicol was added to the synthetic wastewater. Results: The highest count of fungiwith a mean concentration was found in the Aeration tank (149 CFU/ml), whereas the lowest count of fungi wasfound in the Effluent tank (3.3 CFU/ml). The highest diversity of genera (17) was isolated in the Aeration tank,while the lowest diversity of genera (3) was isolated from the Effluent tank. The results of the physical-chemicaltests showed that the average removals of COD, TN, and TP in the IFAS fungal system were 91.76%, 91.43%,and 80.23%, respectively. Conclusions: This study on fungi and their ability in reducing nutrients called attentionto the role of the IFAS system and its potential for developing a new biological nitrogen removal technology basedon fungal treatment.