Feasibility of a multi-component additive for efficient control of activated sludge filamentous bulking

• Published in: Water research (Oxford) 2001-08, Vol.35 (12), p.2995-3003
• Main Authors: Seka, Arsène M., Van de wiele, Tom, Verstraete, Willy
• Format: Article
• Language: English
• Subjects: activated sludge; Applied sciences; Bacteria - growth & development; Biodegradation, Environmental; Biological and medical sciences; Biological treatment of waters; Biotechnology; Coagulants - pharmacology; Environment and pollution; Exact sciences and technology; Feasibility Studies; filamentous bulking; Flocculation; Fundamental and applied biological sciences. Psychology; General purification processes; Industrial applications and implications. Economical aspects; Limicola; Macromolecular Substances; Microscopy; multi-component additive; Oxygen - metabolism; Pollution; polymer; Polymers - pharmacology; quaternary ammonium compound; Quaternary Ammonium Compounds - pharmacology; Sewage - chemistry; Sewage - microbiology; talc; Talc - pharmacology; Wastewaters; Water Microbiology; Water Purification - methods; Water treatment and pollution
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/S0043-1354(00)00589-3

Instantaneous improvement of the settling of bulking filamentous activated sludge can be achieved by the addition of a polymer or a large amount (up to 100% of the MLSS concentration) of talc powder to the sludge. Long-term improvement relies on repeated additions, as these additives have no adverse effects on the causative filaments. A multi-component additive was compared to the traditional additives in lab-scale activated sludge units using three highly filamentous sludges from different industrial treatment plants. The study demonstrated that the multi-component additive was superior to the traditional remedies. It was shown that, in the case of severe filamentous bulking, a single addition of the new additive immediately improved sludge settling and exerted a destructive effect on the causative filamentous bacteria. Thus, the latter additive also ensured a long-term sludge sedimentation improvement. The traditional additives exhibited an immediate and short-term effect. The novel additive also retarded sludge rising due to denitrification and it improved sludge dewaterability. The study revealed Nostocoida limicola II, with slightly hydrophobic cell wall, to be somewhat resistant to the quaternary ammonium salt present as biocide in the additive.