SEMINAR: Towards a comprehensive framework for the management, risk assessment, and mitigation of toxic cyanobacteria in waterways

Mismanagement of the earth’s water resources has resulted in a severe water crisis. One of the major deleterious effects of our anthropogenic inputs to waterways is an increase in eutrophication, which can lead to toxic cyanobacterial blooms. Such blooms are of global concern due to their ability to alter environmental systems, produce toxins, and affect the treatment capacity of water utility plants. Therefore, it is imperative that strategies are devised and implemented to ensure that the occurrence of such blooms ismanaged effectively so as to reduce their impact upon ecological and human communities alike.

This research devised a risk assessment strategy which can be applied to any freshwater system that experiences cyanobacterial blooms, and which can be used to determine the optimum monitoring regime for an individual water resource. Should bloom events of significant risk occur, potential cyanobacterial mitigation methods were also considered. This included a thorough investigation of the potential use of hydrogen peroxide as an algicide for the treatment of cyanobacterial blooms.

A common wastewater treatment technology in both developed and developing countries is the use of waste stabilisation ponds. From the knowledge gathered through the experimental results of myself and others, the existing literature regarding cyanobacterial bloom management, and the newly devised risk assessment methodology, a framework has been developed for managing toxic cyanobacteria in these ponds. It is anticipated that such a framework can be used by water utilities where cyanobacterial blooms pose a threat to humans, the environment, and wastewater treatment processes.