Algae can exhibit different disinfection by-product formation potential (DBPFP) depending on the characteristics of the algogenic organic matter (AOM) released during growth. In this study, the amount of AOM released by Microcystis aeruginosa and its DBPFP were compared between the exponential growth phase and the death phase. Moreover, the efficiency of DBPFP removal through powdered activated carbon (PAC) adsorption was evaluated. The correlations between DBPFPs and dissolved organic carbon concentration or ultraviolet absorbance at 254 nm (UV254) were also investigated to predict DBPFPs. Among DBPFPs, which were higher at the death phase, the formation potential (FP) of haloacetic acid was the highest. In addition, the high relative haloacetonitrile FP at the death phase indicated that a relevant portion of the intracellular organic matter derived from cell autolysis was converted into a large amount of haloacetonitriles. Furthermore, PAC addition reduced all DBPFPs at both growth phases. PAC was found to selectively adsorb dichloroacetic acid precursors at the death phase and dichloroacetonitrile precursors at both growth phases. Finally, UV254 showed greater correlations with the three DBPFPs at all growth phases. These results highlight the possible use of UV254 as an alternative analytical tool for fast determination of M. aeruginosa DBPFPs.
Keywords: Algae; Disinfection by-product; Growth phase; Microcystis aeruginosa; Powdered activated carbon.
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