Abstract Title

Understanding the impact of natural organic matter on microcystin-LR biodegradation and their characterization using fluorescence PARAFAC analysis

Start Date

24-5-2022 5:45 PM

End Date

24-5-2022 7:00 PM

Abstract

The successful application of bioaugmentation (injection of contaminant-degrading microorganisms) can remove harmful cyanotoxins like microcystin-LR (MC-LR) from drinking water sources. However, in natural and engineered water systems, the natural organic matter (NOM) is present in varying concentrations and might affect the bacterial biodegradation of MC-LR. In addition, changes in biomolecular characteristics of NOM during bioaugmentation can affect the treated water quality in drinking water treatment plants (DWTPs). Therefore, for application of bioaugmentation for MC-LR removal in DWTPs, it is important to investigate the impact of NOM on MC-LR biodegradation and corresponding NOM composition changes. In this study, the impact of NOM [algal organic matter (AOM) and humic substances (HS)] on MC-LR biodegradation was evaluated monitoring MC-LR biodegradation kinetics. The changes in NOM composition during MC-LR biodegradation was also characterized using a five component Parallel factor (PARAFAC) model built by 336 Excitation-emission matrix (EEMs) spectra collected at different sampling time. Our results show decrease in MC-LR biodegradation rate by 2.85 and 3.82-fold in the presence of AOM and HS, respectively. EEM-PARAFAC analyses showed a relatively greater production of terrestrial humic-like components (57%) in comparison to control conditions (27%), likely due to the microbial metabolism.

Keywords: Bioaugmentation, Cyanotoxins, Microcystin-LR, EEM-PARAFAC analyses

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May 24th, 5:45 PM May 24th, 7:00 PM

Understanding the impact of natural organic matter on microcystin-LR biodegradation and their characterization using fluorescence PARAFAC analysis

The successful application of bioaugmentation (injection of contaminant-degrading microorganisms) can remove harmful cyanotoxins like microcystin-LR (MC-LR) from drinking water sources. However, in natural and engineered water systems, the natural organic matter (NOM) is present in varying concentrations and might affect the bacterial biodegradation of MC-LR. In addition, changes in biomolecular characteristics of NOM during bioaugmentation can affect the treated water quality in drinking water treatment plants (DWTPs). Therefore, for application of bioaugmentation for MC-LR removal in DWTPs, it is important to investigate the impact of NOM on MC-LR biodegradation and corresponding NOM composition changes. In this study, the impact of NOM [algal organic matter (AOM) and humic substances (HS)] on MC-LR biodegradation was evaluated monitoring MC-LR biodegradation kinetics. The changes in NOM composition during MC-LR biodegradation was also characterized using a five component Parallel factor (PARAFAC) model built by 336 Excitation-emission matrix (EEMs) spectra collected at different sampling time. Our results show decrease in MC-LR biodegradation rate by 2.85 and 3.82-fold in the presence of AOM and HS, respectively. EEM-PARAFAC analyses showed a relatively greater production of terrestrial humic-like components (57%) in comparison to control conditions (27%), likely due to the microbial metabolism.

Keywords: Bioaugmentation, Cyanotoxins, Microcystin-LR, EEM-PARAFAC analyses