Limnochemistry, Aquatic Biology: Self cleaning
basic principles for self-cleaning of waters are as follows:
Graphic example of bacteria metabolism
The structure of the food web has a decisive influence on water quality. Quality is especially determined by availability of plant nutrients (nitrogen and phosphorus compounds), since these control the growth of harmful phytoplanktons (usually single celled algae and cyanobacteria). Phytoplanktons can considerable reduce the quality of untreated water (smell, taste, toxic algae) and can greatly impede the treatment of water in reservoirs. Phytoplankton is the primary producer of basic nutrients for zooplankters, which is eaten by other consumers (fish, predators on zooplanktons). The food cycle through the levels of organism is closed by bacteria which mineralise the biomass into nutrients (Figure, Graphic example).