Evaluating fluorescence and ultraviolet photometry to assess dissolved organic matter removal during coagulation-flocculation

Ultraviolet absorption at 254 nm (UV254) and peaks (A, C and T) fluorescence intensities were evaluated to assess dissolved organic carbon (DOC) removal during coagulation–flocculation. The consistency of fluorescence data was checked to ensure that no inner filter effect, quenching or enhanced intensities affected the data. The decreases in UV254 and peak intensities were calculated in percentage terms between raw and clarified water and compared with measured DOC removal. The results indicate that peak A, peak C, peak T and UV254 exhibit strong linear relationships (R2: 0.91, 0.89, 0.92 and 0.99, respectively) with DOC removal, implying that these parameters are useful indicators of DOC removal.