What is a pathogen
Pathogens are defined as organisms that can cause disease in their host. The symptoms and severity of disease that can be caused are called virulence. The more virulent a pathogen is, the more dangerous it is.
The number of known pathogens is tremendous and their taxonomic diversities include viruses, bacteria, single-celled and multicellular eukaryotes. In addition to being everywhere, pathogens affect all living organisms in existence, including bacteria that are targeted by specialized viruses
Where do they come from?
Since there is a tremendous amount of different pathogens, their origins vary greatly. However, human pathogens are largely derived from fecal matter.
Treatment of pathogens
When treating pathogens in water, two different approaches exist. Either the deactivation or the extraction of these. Besides, it may be necessary to use both methods if the concentration of pathogens is too high.
In short, as the name implies, extraction methods are used to remove different pathogens from the water. Among the methods of pathogen extraction are coagulation, flocculation and sedimentation. Then, some pathogens can also be extracted by ion exchangers. Other types of filtration such as ultrafiltration and nanofiltration can also extract various types of pathogens. Finally, reverse osmosis is very effective in removing these contaminants.
Deactivation, on the other hand, involves the addition of chemicals or the emission of radiation to eliminate the reproductive capacity of pathogens. Among the types of deactivation that can be used, UV irradiation is a good choice. Secondly, the use of oxidizing products such as chlorine and its derivatives or ozone is very frequently used.
As mentioned above, a combination of technologies may be necessary since pathogen deactivation can leave a large amount of "dead bodies" in the water. The separation technology will then separate these dead bodies from the treated water.