title: Fate of surfactants in membrane bioreactors and conventional activated sludge plants.
abstract: Two membrane bioreactors (MBRs) were operated at high sludge retention time (SRT) (between 30 and 75 d) in parallel to a conventional activated sludge plant (CASP) conducted at SRT = 10 d. The fate of linear alkylbenzene sulfonate (LAS), nonylphenol ethoxylates (NP(n)EO, n = 1-15), nonylphenoxy carboxylates (NP(n)EC, n = 1-2), and nonylphenol (NP) in these systems was investigated. All systems were very efficient in the removal of LAS (around 99%). The analysis of variance showed that the difference in the removal efficiency of LAS in the CASP and the MBR operated at SRT = 65-75 d (respectively 99.0 ± 0.43 and 99.8 ± 0.11) were significant (p < 0.05), confirming the importance of SRT in the removal of LAS. Comparison between the CASP and the MBRs in the removal efficiency of nonylphenolic compounds were conducted considering NP(3-15)EO, the sum of NP(1-15)EO, NP(1-2)EC, and nonylphenol (NP). In all cases MBRs were more efficient than the CASP. In the case of NP the removal was about 76 ± 7.5% for the CASP and 90% ± 12.1 and 82 ± 8.7% for the MBRs. Better performance of MBRs in the removal of nonylphenolic compounds can be attributed to a better degradation. For example, if the sum of NP(1-15)EO and NP(1-2)EC is considered, estimated biodegradation was about 48% for the CASP and 72% for MBRs.
authors.affiliation: Department of Civil and Environmental Engineering, University of Florence, via S. Marta, 3, 50139 Florence, Italy. riccardo.gori@dicea.unifi.it
authors.forename: Riccardo
authors.initials: R
authors.lastname: Gori
authors.forename: Laura
authors.initials: L
authors.lastname: Cammilli
authors.forename: Mira
authors.initials: M
authors.lastname: Petrovic
authors.forename: Susana
authors.initials: S
authors.lastname: Gonzalez
authors.forename: Damià
authors.initials: D
authors.lastname: Barcelò
authors.forename: Claudio
authors.initials: C
authors.lastname: Lubello
authors.forename: Francesca
authors.initials: F
authors.lastname: Malpei
mesh_terms: D019149:Bioreactors; D012722:Sewage / Q000737:chemistry*; D013501:Surface-Active Agents / Q000032:analysis* / Q000378:metabolism; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D012722:Sewage; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical