title: Can those organic micro-pollutants that are recalcitrant in activated sludge treatment be removed from wastewater by biofilm reactors (slow sand filters)?
abstract: The degradation of seven compounds which are usually recalcitrant in classical activated sludge treatment (e.g., diclofenac, propranolol, iopromide, iohexol, iomeprol tebuconazole and propiconazole) was studied in a biofilm reactor (slow sand filtration). This reactor was used to treat real effluent-wastewater at different flow rates (hydraulic loadings) under aerobic conditions so removal and degradation kinetics of these recalcitrant compounds were calculated. With the hydraulic loading rate of 0.012 m(3)m(2)h(-1) the reactor removed 41, 94, 58, 57 and 85% of diclofenac, propranolol, iopromide, iohexol and iomeprol respectively. For these compounds the removal efficiency was dependent on hydraulic residence-times. Only 59 and 21% of the incoming tebuconazole and propiconazole respectively were removed but their removal did not depend on hydraulic residence time. Biofilm reactors are thus efficient in removing micro-pollutants and could be considered as an option for advanced treatment in small wastewater treatment plants.
authors.affiliation: Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
authors.forename: Mònica
authors.initials: M
authors.lastname: Escolà Casas
authors.affiliation: Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark. Electronic address: kb@dmu.dk.
authors.forename: Kai
authors.initials: K
authors.lastname: Bester
mesh_terms: D000332:Aerobiosis; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology*; D005374:Filtration / Q000379:methods; D007700:Kinetics; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D012822:Silicon Dioxide; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry* / Q000382:microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D012722:Sewage; D012822:Silicon Dioxide; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Aerobic degradation; Biofilm reactors; Kinetics; Pesticides; Pharmaceuticals; Wastewater