Impact of the filamentous fungi overgrowth on the aerobic granular sludge process. (September 2019)

• Record Type: Journal Article
• Authors: Sharaf, Ahmed; Guo, Bing; Liu, Yang
• Is Part Of: Bioresource technology reports. Volume 7(2019)
• Publication Date: 2019-09
• Subjects: Aerobic granular sludge -- Filamentous fungi overgrowth -- Microbial community -- Granules stability -- Wastewater treatment; Biomass energy -- Periodicals; Biotransformation (Metabolism) -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Waste products as fuel -- Periodicals; Waste products as fuel; Organic wastes; Factory and trade waste; Biotransformation (Metabolism); Biomass energy; Agricultural wastes; Periodicals; Electronic journals; 662.88
• DOI: 10.1016/j.biteb.2019.100272
• Languages: English
• ISSNs: 2589-014X

Abstract

Abstract: The aerobic granular sludge wastewater treatment technology has numerous advantages as compared to the conventional flocculent sludge technologies. However, the filamentous fungi overgrowth (FFO) is a major operational problem that is hindering its widespread application. This study evaluated the behaviour and mechanisms of the FFO, and its impact on granulation, treatment performance and microbial community structure. The overgrown filamentous organisms were developed in an aerobic granular sludge reactor operated for 274 days. The filamentous organisms were identified to be yeast-like fungi belonging to the moulds Geotrichum of the phylum Ascomycota . The removal of carbon and nitrogen were slightly affected, while phosphorus removal was largely impacted. The FFO development was found to disrupt the structural integrity of granules, cause their disintegration and washout, and lead to a microbial community shift towards a structure lacking bacteria genus that are essential for efficient granulation. Limitations of the currently used routine measurements were discussed. Graphical abstract: Unlabelled Image Highlights: The fungal overgrowth resulted in AGS disintegration and washout. Traditional measures lack sensitivity to early detection of the fungal overgrowth. Nutrients removal efficiency was significantly impacted by the fungal overgrowth. Healthy AGS microbial community was predominated by Thauera and Tubulinea . Filamentous AGS was dominated by yeast-like fungi belonging to Geotrichum .