Dear Kani

your question is too broad. I believe that all parameters mentioned in software called "Quale2" should be considered.

karbassi

thank you so much for the reminder about the quale2

Here some papers on self-purification in rivers.

Best wishes,

Tatiana

Self-purification the ability of rivers to purify itself of contaminants by natural processes. It is produced by certain processes which work as rivers move downstream. These mechanisms can be inform of dilution of polluted water with influx of surface and groundwater or through certain complex hydrologic, biologic and chemical processes such as sedimentation (behind obstruction), coagulation, volatilization, precipitation of colloids and its subsequent settlement at the base of the channel, or lastly due to biological uptake of pollutants.

there are two broad stages of self-purification (1) reversible stage (ii) irreversible stage

the reversible stage of self purification is the stage at which the natural processes of a river can easily deal with incoming pollutants within a considerable stretch of the river.

the irreversible stage is when the rate of contamination exceeds the natural capacity of the river, and thus restoration can practically be achieved by evacuation of wastes.

Dr. Kani,

Please read the following articles. These are useful.

1) Self-purification of organic domestic discharge: nature and effect of residual organic matter in rivers

https://irsteadoc.irstea.fr/oa/PUB00007509-auto-epuration-des-rejets-organiques-domestiques-n.html

2) On the Biotic Self-purification of Aquatic Ecosystems: Elements of the

https://www.researchgate.net/publication/200567576_On_the_Biotic_Self-purification_of_Aquatic_Ecosystems_Elements_of_the_Theory_httpswwwresearchgatenetpublication200567576

3) Simulation of hyporheic self-purification in rivers: the assimilative capacity of proteins.

https://www.ncbi.nlm.nih.gov/pubmed/11379136

Regards