Decentralized Algae Removal Technologies for Lake Diefenbaker Irrigation Canals: A Review

Lake Diefenbaker Irrigation Canals in Canada are crucial in providing water for irrigation, preventing droughts and floods, and supporting the Saskatchewan agriculture industry and economy. Unfortunately, filamentous algal blooms occur every summer in Lake Diefenbaker Irrigation Canals. These algae are not toxic but a nuisance. They block farmers’ pumps and reduce irrigation water flow rates. Currently, the Water Security Agency periodically adds the algaecide Magnacide H. to control the algal blooms, which is costly (i.e., one million dollars per year for the Lake Diefenbaker M1 Irrigation Canal only) and requires effort to dewater the canal to protect fish. Therefore, algae removal before the canal water enters farmer’s pumps might be a cost-effective alternative, especially the removal of microalgae during the initial stages of growth in June of each year. This paper has summarized and evaluated algae removal technologies, considering their advantages, disadvantages, and potential solutions for addressing the challenges and limitations associated with these technologies. Five algae removal technologies were identified as promising, which are suspended air flotation (SAF), dissolved air flotation (DAF), hydrodynamic cavitation, spiral blade centrifuge, and coagulation. Among them, SAF seems the most suitable option, while DAF and hydrodynamic cavitation offer eco-friendly advantages. Further research and pilot testing are needed to determine the costeffective and feasible algae removal technology for Lake Diefenbaker Irrigation Canals.