Purification of Household Wastewater

Household wastewater goes into sewage from kitchens, bathrooms etc. Such wastewater can be treated using mechanical and biological methods.

Purification of wastewater is a complex multistage process, which begins in the input chamber. Then the water is filtered mechanically to remove garbage etc. The liquid phase is separated from the solid phase, by using settling tanks, grates, sand traps etc. Mechanical influence is only a preliminary stage before biological purification.

Microbial metabolism removes organic contaminants from the wastewater. The biological treatment facilities are of two types:

  • with conditions close to natural (natural biological treatment);
  • with artificial conditions (artificial  biological treatment).

Natural bio treatment can be performed in sewage farms, oxidation ponds etc, while artificial measures include aero and biofilters, as well as aerotanks. In the latter case, all purification processes are mode intensive, due to better conditions for microbial life.

A biological filter is a special structure where wastewater is filtered by passing through material covered with a biological film. This film is made up of microbial colonies.

Aerotanks are long rectangular concrete vessels with slow motion of mixed wastewater and biological sludge. Air is supplied to the tank so that the microbes can function, which does not only supply oxygen, but also maintains the activity of the sludge.

After dehydration, the sediment from wastewater may be used in agriculture as organic fertilizer, but only if it contains no toxic waste, such as heavy metals.

обновлено: January 6, 2017 автором: dannik