This project increased understanding of how cyanobacteria adapt and function in today’s environment. It provided insight to the key factors that contribute to growth of Microcystis and Anabaena in relation to physical conditions of the reservoir and reduced as well as predicted the occurrence and toxicity of blooms by understanding toxin regulation.

PhD Thesis completed by Anna Chi Ying Yeung in August 2016.

This project developed novel sampling tools to allow time integrated passive sampling of existing and emerging chemicals pollutants. Sampling devices developed through this work assisted with more comprehensive and cost-effective monitoring of newly recognised potential toxicants in surface and treated water across Australia.

Honours Thesis completed by Sarit Kaserzon in 2014.

Blue-green algae (cyanobacteria) can bloom in marine and freshwater and cause additional problems for water utilities when they produce toxins and taste and odour compounds. This project consolidated a wealth of knowledge and experience in the management of cyanobacteria into an electronic / online international, practical, and user-friendly manual. It includes information about conducting risk assessments, developing monitoring programmes and incident management strategies, and management procedures to mitigate the risk posed by cyanotoxins.

‘PFAS’ are a large class of chemical compounds, some of which can bioaccumulate or be toxic to humans and animals. Three PFAS: PFOS, PFOA and PFAS3; have been comprehensively investigated. An earlier study (WaterRA Project 2046) found PFAS in recycled wastewater and this raised concerns that crops irrigated with recycled water might lead to long-term chronic toxicity or bioaccumulation in soils. This research used existing datasets about PFOS, PFOA and PFAS3 to build a predictive conceptual model: the PFAS Exposure Model for Irrigation (PEMI). This was used to derive ‘Trigger Points for Investigation’(TPI); the levels of PFOS or PFOA or PFAS3 that, when measured in soil or recycled water, are high enough to cause concern and trigger investigation and action. Levels lower than the TPI’s are considered ‘safe’, and the PFAS3 TPI was higher than the median concentration measured in recycled wastewater from 17 Australian treatment plants (Project 2046). While these TPI are an excellent start to ongoing environmental and safety monitoring, the authors note that more data and research about plant uptake, animal transfer, degradation and leaching of additional PFASs will help validate and improve the PEMI.

Cyanobacteria are blue-green algae that can bloom and grow to the extent that their green-coloured cells are visible both within and on top of water bodies. The algal cells, and the toxins they contain, must be removed before releasing treated wastewater to the environment, or during the production of safe drinking water. Oxidizing agents (chemicals) are used to kill the algae and destroy their toxins but other components in the water, including organic matter, can interfere with the efficacy of the chemicals. This project identified water components that influence algal cell treatment and removal, and determined the most appropriate types and amounts of chemicals to use in different situations.