title: Environmental performance of an integrated fixed-film activated sludge (IFAS) reactor treating actual municipal wastewater during start-up phase.
abstract: The present study summarizes the start-up performance and lessons learned during the start-up and optimization of a pilot-scale plant employing integrated fixed film activated sludge (IFAS) process treating actual municipal wastewater. A comprehensive start-up was tailored and implemented to cater for all the challenges and problems associated with start-up. After attaining desired suspended biomass (2,000-3,000 mg/L) and sludge age (∼7 days), the average biological oxygen demand (BOD) and chemical oxygen demand (COD) removals were observed as 77.3 and 70.9%, respectively, at optimized conditions, i.e. hydraulic retention time (HRT), 6.9 h; return sludge rate, 160%. The influent concentrations of COD, BOD, total suspended solids, NH3-N, total nitrogen and total phosphorus were found to be in the range of 157-476 mg/L, 115-283 mg/L, 152-428 mg/L, 23.2-49.3 mg/L, 30.1-52 mg/L and 3.6-7.8 mg/L, respectively, and the minimum effluent concentrations were achieved as ∼49 mg/L, 23 mg/L, 35 mg/L, 2.2 mg/L, 3.4 mg/L and 2.8 mg/L, respectively, at optimum state. The present system was found effective in the removal of pathogenic bacteria (Escherichia coli, 79%; Salmonella spp., 97.5%; Shigella spp., 92.9%) as well as coliforms (total coliforms, 97.65%; faecal coliforms, 80.35%) without any disinfection unit. Moreover it was observed that the time required for the stabilization of the plant was approximately 3 weeks if other parameters (sludge age, HRT and dissolved oxygen) are set to optimized values.
authors.affiliation: Environmental Engineering Group, Department of Civil Engineering, Indian Institute of Technology, Roorkee, 247667, India E-mail: nitin261187@gmail.com.
authors.forename: Nitin Kumar
authors.initials: NK
authors.lastname: Singh
authors.affiliation: Environmental Engineering Group, Department of Civil Engineering, Indian Institute of Technology, Roorkee, 247667, India E-mail: nitin261187@gmail.com.
authors.forename: Absar Ahmad
authors.initials: AA
authors.lastname: Kazmi
authors.affiliation: Competence Centre for Decision-Aid in Environmental Management, University of Natural Resources and Life Sciences/ DIB, Gregor Mendel Strasse 33, A-1180 Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Starkl
mesh_terms: D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D019149:Bioreactors; D004926:Escherichia coli / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D009584:Nitrogen / Q000032:analysis; D010100:Oxygen / Q000737:chemistry; D010758:Phosphorus / Q000032:analysis; D012475:Salmonella / Q000302:isolation & purification; D012722:Sewage / Q000737:chemistry; D012760:Shigella / Q000302:isolation & purification; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D062065:Wastewater / Q000382:microbiology*
chemical_list: D009584:Nitrogen; D010100:Oxygen; D010758:Phosphorus; D012722:Sewage; D062065:Wastewater