title: Fate of NDMA precursors through an MBR-NF pilot plant for urban wastewater reclamation and the effect of changing aeration conditions.
abstract: The removal of N-nitrosodimethylamine (NDMA) formation potential through a membrane bioreactor (MBR) coupled to a nanofiltration (NF) pilot plant that treats urban wastewater is investigated. The results are compared to the fate of the individual NDMA precursors detected: azithromycin, citalopram, erythromycin, clarithromycin, ranitidine, venlafaxine and its metabolite o-desmethylvenlafaxine. Specifically, the effect of dissolved oxygen in the aerobic chamber of the MBR pilot plant on the removal of NDMA formation potential (FP) and individual precursors is studied. During normal aerobic operation, implying a fully nitrifying system, the MBR was able to reduce NDMA precursors above 94%, however this removal percentage was reduced to values as low as 72% when changing the conditions to minimize nitrification. Removal decreased also for azithromycin (68-59%), citalopram (31-17%), venlafaxine (35-15%) and erythromycin (61-16%) on average during nitrifying versus non-nitrifying conditions. The removal of clarithromycin, o-desmethylvenlafaxine and ranitidine could not be correlated with the nitrification inhibition, as it varied greatly during the experiment time. The MBR pilot plant is coupled to a nanofiltration (NF) system and the results on the rejection of both, NDMA FP and individual precursors, through this system was above 90%. Finally, results obtained for the MBR pilot plant are compared to the percentage of removal by a conventional full scale biological wastewater treatment plant (WWTP) fed with the same influent. During aerobic operation, the removal of NDMA FP by the MBR pilot plant was similar to the full scale WWTP.
authors.affiliation: Chemical and Environmental Engineering Laboratory (LEQUIA), Institut de Medi Ambient, Campus Montilivi s/n, University of Girona, E-17071, Girona, Catalonia, Spain.
authors.forename: Julian
authors.initials: J
authors.lastname: Mamo
authors.affiliation: Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, H(2)O Building, Emili Grahit 101, 17003, Girona, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Insa
authors.affiliation: Chemical and Environmental Engineering Laboratory (LEQUIA), Institut de Medi Ambient, Campus Montilivi s/n, University of Girona, E-17071, Girona, Catalonia, Spain.
authors.forename: Hèctor
authors.initials: H
authors.lastname: Monclús
authors.affiliation: Chemical and Environmental Engineering Laboratory (LEQUIA), Institut de Medi Ambient, Campus Montilivi s/n, University of Girona, E-17071, Girona, Catalonia, Spain; Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, H(2)O Building, Emili Grahit 101, 17003, Girona, Spain.
authors.forename: Ignasi
authors.initials: I
authors.lastname: Rodríguez-Roda
authors.affiliation: Chemical and Environmental Engineering Laboratory (LEQUIA), Institut de Medi Ambient, Campus Montilivi s/n, University of Girona, E-17071, Girona, Catalonia, Spain; Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, H(2)O Building, Emili Grahit 101, 17003, Girona, Spain.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Comas
authors.affiliation: Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, H(2)O Building, Emili Grahit 101, 17003, Girona, Spain; Water and Soil Quality Research Group, Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034, Barcelona, Spain.
authors.forename: Damià
authors.initials: D
authors.lastname: Barceló
authors.affiliation: Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, H(2)O Building, Emili Grahit 101, 17003, Girona, Spain. Electronic address: mjfarre@icra.cat.
authors.forename: Maria José
authors.initials: MJ
authors.lastname: Farré
mesh_terms: D019149:Bioreactors; D004128:Dimethylnitrosamine; D008567:Membranes, Artificial; D058465:Nitrification; D014865:Waste Disposal, Fluid; D062065:Wastewater; D018508:Water Purification
chemical_list: D004128:Dimethylnitrosamine; D008567:Membranes, Artificial; D062065:Wastewater
keywords: Membrane bioreactor; N-nitrosamine; NDMA precursor; Nitrification; On-line analysis