Alternative cyanobacteria management approaches

摘要

Aeration is conventionally used to prevent cyanobacteria blooms in source water storages but is often prohibitively expensive. There are several treatment products on the market that may offer an alternative approach to cyanobacteria bloom prevention by manipulating the microbial ecology of a lake. WaterNSW recently tested selected treatment products in a 2-week laboratory study and a 10-week field study. The trials assessed how well the products controlled cyanobacterial growth, and their potential for adverse effects on water quality, treatability and ecological health. The laboratory trials provided some evidence to support the effectiveness and mode of action for specific treatments. However, the field trial found that destratification still had the strongest influence on cyanobacterial growth relative to other tested treatments. The trials provided many useful learnings regarding the effectiveness and safety of the treatment products, the circumstances where specific treatments might best be suited for deployment and the design of any future trials. The outcomes of this work will be used to evaluate the potential of these products for future use in managing cyanobacterial blooms in WaterNSW’s supply storages.