Influence of the nutrient balance on biofilm composition in a fixed film process

• Published in: Water Science & Technology Vol. 46; no. 4-5; pp. 7 - 12
• Main Authors: HENDRICKX, T. L. G, MESKUS, E, KEISKI, R. L
• Format: Conference Proceeding Journal Article
• Language: English
• Published: London IWA 01-01-2002; IWA Publishing
• Subjects: Applied sciences; Bacteria; Biofilms; Biofilters; Biological and medical sciences; Biological treatment of waters; Biomass; Biotechnology; Composition; Environment and pollution; Exact sciences and technology; Experimentation; Finland, Oulu; Fixed-film process; Fundamental and applied biological sciences. Psychology; Fungi; Fungi - growth & development; Fungi - physiology; General purification processes; Growth; Industrial applications and implications. Economical aspects; Influents; Mineral nutrients; Nutrient availability; Nutrient balance; Nutrients; Operational problems; Organic Chemicals; Organic phosphorus; Phosphoric acid; Phosphorus; Phosphorus - metabolism; Phosphorus removal; Pollution; Population Dynamics; Removal; Uptake; Waste Disposal, Fluid; Wastewater; Wastewater treatment; Wastewater treatment plants; Wastewaters; Water treatment; Water treatment and pollution; Water treatment plants; Finland; Finland, Oulu, Oulu; Fungi; Bioreactor; Upward flow; Biofilm; Nutrient; Biofilter; Waste water purification; Experimental study; Material balance; Thallophyta; Biological purification
• ISBN: 9781843394235; 1843394235
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2002.0538

An attached fungal growth has appeared in a fixed biofilm process at the waste water treatment plant of the City of Oulu, Finland. Due to the filamentous morphology of the fungi, biofilm support material is easily washed out. The appearance is believed to be the result of the unbalanced availability of nutrients, where phosphorus has been identified as the key component. Experimental work concentrated on the influence of phosphorus on the fungal growth. Bench scale experiments showed that a higher uptake of phosphorus for the removal of organic material is possible, which also resulted in a suppression of the fungal growth by bacterial biomass. The results were confirmed by experimentation in a full-scale biofilter. Addition of extra phosphoric acid to the biofilter influent resulted in a biofilm where the fungal growth is less pronounced. The fungal growth is believed to be competitive with the desired bacterial growth. It is possible to keep the fungal growth within limits by changing the conditions in favour of the bacterial growth, thus avoiding the operational problems connected with the filamentous fungi.