Assessment of cyanobacteria and their taste and odorous metabolites in the lower River Murray: 2000–2022

Abstract

Cyanobacteria continue to contribute to the taste and odor issues (T&O) in the lower River Murray. A review on the cyanobacteria and T&O data collected in the last 22 years showed that there has been a shift in cyanobacterial community and subsequent T&O profiles. The increased numbers and changes in cyanobacteria occurrence have likely influenced the resultant T&O profiles. T&O challenges started occurring more frequently post-2015. Although the river has historically been affected by geosmin challenges, up to 999 ng/L of geosmin and 155 ng/L of 2-methylisoborneol (MIB) concentrations that have been detected along the river. Findings from this study showed that of the 22 water treatment plants investigated, the more advanced ultrafiltration membrane and granular activated carbon system treatment plants were able to mitigate most of the T&O challenges whereas the conventional water treatment plants were more likely to have T&O breakthrough instead.