Assessing removal efficiency of dissolved organic matter in wastewater treatment using fluorescence excitation emission matrices with parallel factor analysis and second derivative synchronous fluorescence

To assess removal efficiency of dissolved organic matter (DOM) in the wastewater treatment plant (WWTP), fluorescence excitation emission matrices (EEM) with parallel factor analysis (PARAFAC) and second derivative synchronous fluorescence (SDSF) were used for the characterization of DOM in wastewater. In A2/O process, tryptophan-like and tyrosine-like materials were removed to the much greater extent than that of fulvic-like. The protein-like material might be mostly decomposed by anaerobic and aerobic bacteria in anaerobic/anoxic and oxic zones. C1, C2, I276, I286, AP1 and AP2 were much better in tracing variations of tryptophan-like and tyrosine-like materials than C3, I329 and AF1 in tracing fulvic-like. The number of sampling sites should be reduced, as concentration variations of DOM components were subtle among sampling sites in the oxic zone and secondary sedimentation tank. SDSF may be a useful tool as PARAFAC to monitor removal efficiency of DOM fractions from wastewater in the WWTP.