What needs to be reduced from the liquid effluent?

It contains large amounts of organic molecules and harmful microorganisms - both of these need to be reduced before the water is returned to the environment

How is liquid effluent safely returned to the environment?

air is bubbled through the liquid effluent and this allows aerobic bacteria to multiply and in the presence of oxygen, the aerobic bacteria digest the organic molecules and harmful microorganisms - after this stage, the liquid effluent can be safely discharged into nearby rivers or the sea

how is waste water treated?

sewage is screened by passing through a mesh to remove solids and pieces of grit - the sewage is now allowed to settle in large sedimentation tanks and this now produces a liquid effluent and a semi-solid sludge which sinks - the sludge is then taken away and digested by anaerobic bacteria and in the absence of oxygen, these bacteria produce biogas - the digested sludge can be used as fertilisers for farming

what can biogas be used for?

can be burned for electricity

sedimentation

The action or process of forming deposing sediment

Filtration

A process that separates materials based on the size of their particles

Sterilising

A process that involves removing all pathogens that can cause infections

Desalination

A process of removing salt from ocean water

Distilisation

A process that seperates the substances in a solution based on their boiling points

Reverse Osmosis

A desalinization process that involves forcing salt-water through a membrane permeable to water but not to salt

atmosphere earth today

Nitrogen- 78% Oxygen-21% argon-0.93% traces-hydrogen,helium