Release behavior of odor contaminants derived from Microcystis aeruginosa in rivers and a non-strict anaerobic aqueous system

Data were collected and reviewed to assess the odorous contaminant status of drinking water sources for Hangzhou City, China. β -Cyclocitral, β -ionone, dimethyl trisulfide, 2-methylisoborneol, and geosmin were targeted odorants. Results indicate that β -cyclocitral was the main contaminant in source waters as it was most frequently detected and occurred at higher concentrations compared to other odorants. Cyanophyta, including Oscillatoria , Microcystis , and Anabaena , were detected in river source waters. The origin of β -cyclocitral was also investigated in the laboratory by simulated non-strict anaerobic experiments using a prevalent species, Microcystis aeruginosa . Under non-strict anaerobic conditions, M. aeruginosa released primarily β -cyclocitral and β -ionone. Correlation of β -cyclocitral and cyanobacteria counts in the laboratory provide an explanation for high β -cyclocitral concentrations in source waters. For a M. aeruginosa cell concentration of 106 cells/L, average release and potential β -cyclocitral concentration were 49 and 44 ng/L. For 107 cells/L, the values increased to 725 ng/L and 545 ng/L, respectively. Environmental conditions, including temperature, pH, and illumination, exhibited substantial impact on cyanobacterial production of β -cyclocitral in aqueous systems.