title: A logistic model for the remediation of filamentous bulking in a biological nutrient removal wastewater treatment plant.
abstract: Biological nutrient removal (BNR) systems across the globe frequently experience bulking and foaming episodes, which present operational challenges such as poor sludge settling due to excessive filamentous bacteria. A full-scale BNR plant treating primarily domestic wastewater was monitored over a period of 1 year to investigate filamentous bacterial growth response under various plant operating parameters. Identification of filamentous bacteria by conventional microscopy and fluorescent in situ hybridisation indicated the dominance of Eikelboom Type021N, Thiothrix spp., Eikelboom Type 1851 and Eikelboom Type 0092. A cumulative logit model (CLM) was applied to elucidate significant relationships between the filamentous bacteria and plant operational parameters. The model could predict the potential abundance of dominant filamentous bacteria in relation to wastewater treatment plant operational parameters. Data obtained from the model corroborated with previous findings on the dominance of most filaments identified, except for Type 0092, which exhibited some unique traits. With further validation, the model could be successfully applied for identifying specific parameters which could contribute towards filamentous bulking, thus, providing a useful tool for regulating specific filamentous growth in full-scale wastewater treatment plants.
authors.affiliation: Institute for Water and Wastewater Technology, Durban University of Technology, Durban, South Africa E-mail: faizalb@dut.ac.za.
authors.forename: Nashia
authors.initials: N
authors.lastname: Deepnarain
authors.affiliation: Institute for Water and Wastewater Technology, Durban University of Technology, Durban, South Africa E-mail: faizalb@dut.ac.za.
authors.forename: Sheena
authors.initials: S
authors.lastname: Kumari
authors.affiliation: Division of Epidemiology and Biostatistics, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: Jordache
authors.initials: J
authors.lastname: Ramjith
authors.affiliation: Institute for Water and Wastewater Technology, Durban University of Technology, Durban, South Africa E-mail: faizalb@dut.ac.za.
authors.forename: Feroz Mahomed
authors.initials: FM
authors.lastname: Swalaha
authors.affiliation: Water Research Institute, CNR, Rome, Italy.
authors.forename: Valter
authors.initials: V
authors.lastname: Tandoi
authors.affiliation: Institute for Water and Wastewater Technology, Durban University of Technology, Durban, South Africa E-mail: faizalb@dut.ac.za.
authors.forename: Kriveshin
authors.initials: K
authors.lastname: Pillay
authors.affiliation: Institute for Water and Wastewater Technology, Durban University of Technology, Durban, South Africa E-mail: faizalb@dut.ac.za.
authors.forename: Faizal
authors.initials: F
authors.lastname: Bux
mesh_terms: D001419:Bacteria / Q000254:growth & development*; D057219:Biofouling; D019149:Bioreactors; D017404:In Situ Hybridization, Fluorescence; D008962:Models, Theoretical; D012722:Sewage / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000382:microbiology*
chemical_list: D012722:Sewage; D062065:Wastewater