how is it relate to water qualit
this phenomenon was widespread with dramatic fish kills and large segments of slow-moving rivers and lakes becoming almost abiotic because of high BOD caused by pollution. The procedures followed in this exercise involve the collection of water and the measurement of dissolved oxygen and pH at the time of the collection. The samples are placed in bottles full to the brim and sealed off by a lid. The sample bottles are covered completely with aluminum foil and placed in a dark place. This limits the photosynthesis, which could happen with captured algae. After five days, the bottles are uncorked and the dissolved oxygen is probed. The difference between the first and the last of the samples is called the BOD. A low number generally means little pollution and/or little aerobic activity. A high BOD means the opposite.