Sewage Treatment

Created by

Rachel Sharp

Cards (9)

Sewage Treatment Steps
Preliminary Treatment
Primary Treatment
Secondary Treatment
Tertiary Treatment
Discharge
Sewage Treatment
Preliminary Treatment - Screening to remove any large particles. Channels and tanks remove grit and sand.
Primary Treatment - Sedimentation to remove remaining solids. Particles settle on bottom of the tank to form sludge. Semi-liquid sludge is collected and sewage liquor remains, and passes onto the next stage.
Secondary Treatment - Biological oxidation using micro-organisms and aeration to removes dissolved and suspended organic matter. Sludge is removed and treated. Liquor passes to the next stage.
Tertiary Treatment - Filtration to remove remaining suspended matter and toxins from liquor, now known as effluent. Disinfection using UV light. Not always applied.
Discharge - Effluent discharged to seas and rivers.
Sewage Treatment Preliminary Treatment
Screening to remove any large particles. Channels and tanks remove grit and sand
Sewage Treatment Primary Treatment
Sedimentation to remove remaining solids. Particles settle on bottom of the tank to form sludge. Semi-liquid sludge is collected and sewage liquor remains, and passes onto the next stage.
Sewage Treatment Secondary Treatment
Biological oxidation using micro-organisms and aeration to removes dissolved and suspended organic matter. Sludge is removed and treated. Liquor passes to the next stage.
Sewage Treatment Tertiary Treatment
Filtration to remove remaining suspended matter and toxins from liquor, now known as effluent. Disinfection using UV light. Not always applied.
Sewage Treatment Discharge
Effluent discharged to seas and rivers.
SEPA monitor waters to ensure they're not polluted and treatment is effective.
End uses of sludge
Heat treated and used as fertiliser.
Turned into sludge cake and used for energy production through incineration.
Anaerobic digester to create biogas which is then used for heat and electricity production.