LAUSR

Abstract In this work, the textile wastewater samples along two full-scale treatment trains (‘biological + oxidative’ process) were characterized by fluorescence excitation emission matrix (EEM). Four fluorescent components (C1–C4) were identified by parallel factor (PARAFAC) analysis. The polarity and apparent molecular weight (MW) of C1–C4 were investigated by high performance liquid chromatography (HPLC). By comparison of EEM spectra and HPLC chromatograms, the tyrosine-like component (C1) and the tryptophan-like components (C2 and C3) were related to Dispersant MF. Component C4 with two emission peaks suggested the formation of an intramolecular exciplex. Despite the remarkable difference of untreated textile wastewater, the polarity and apparent MW of C1–C4 as well as their variations along the treatment trains were highly similar between different wastewater treatment plants. The weights distribution of Dispersant MF among C1–C4 indicates its dominance in the protein-like fluorescence of textile wastewater. Component C1–C4 had different fate in various treatment stages. C1–C4 were poorly removed (