A case study of low pressure air flotation ferryboat for algae removal in Korean rivers and lakes

[Display omitted] •Low pressure flotation system was installed on a ferryboat for removing algae.•High speed collision at low pressure in microbubble generator.•Poly aluminum chloride was used as a coagulant.•Stainless steel screen removed water from algae flocs. In recent years, blue-green algae issue has been one of the most important problems in many rivers in Korea. In this regard, our study investigated the algae removal process using low pressure air flotation (LAF) system installed on a ferryboat. Using high speed collision for microbubble generator, LAF employed lower pressure as 1.5kgf/cm2. The experiments were conducted in Han River and Daecheong Dam. LAF system ferryboat obtained Chl-a removal efficiency of 99%, while COD and T-P removal efficiencies fluctuated from 80% to 97%.