Oxygen consumption
Oxygen consumption (also oxygen consumption rate) is the decrease in oxygen per time period (e.g. in mg / (L · min)) in the water due to the respiration and breakdown processes of organisms . A high oxygen consumption rate indicates a high activity of the organisms, so that a high level of pollution of the water with organic, biochemically convertible substances can be concluded.
By measuring the oxygen consumption, conclusions can also be drawn about the proper functioning or activity of the biomass in a biological purification stage in a sewage treatment plant .
The metabolic activity of aquatic organisms in natural waters depends heavily on climatic conditions (e.g. solar radiation or temperature), in aquaculture facilities on the feed input or time. The measured oxygen value can therefore be subject to strong fluctuations depending on the time of day and time of year. This must be taken into account when taking samples or measuring.