Effect of Rainfall and pH on Musty Odor Produced in the Sanbe Reservoir

Harmful cyanobacterial blooms are continuously formed in water systems such as reservoirs and lakes around the world. Geosmin 2-methylisoborneol (2-MIB) produced by some species of cyanobacteria have caused odor problems drinking Sanbe Reservoir Japan. Field observations were conducted for four years (2015–2019) to investigate cause this musty odor. It was found that geosmin Dolichospermum crassum planctonicum (cyanobacteria), 2-MIB due Pseudanabaena sp. Aphanizomenon cf. flos-aquae (cyanobacteria). Changes temperature pH rainfall correlated with changes concentration 2-MIB. In particular, tended occur under low conditions. When there rainfall, reservoir changed an alkaline state because phytoplankton consumed CO2 photosynthesis. reservoir, dissolved inorganic carbon mainly existed form bicarbonate (HCO3−). Thus, results suggest conditions reservoirs, grew easily they could use both HCO3− Specifically, our study suggests order problem be solved, it is important controlled.