Melbourne Sewage System Western Treatment plant Eastern treatment Plant Regional treatment plans
Western Treatment plant • Primary Treatment • Sludge • Grass Filtration • Land Filtration • Lagooning • Aerobic • Facultative
Primary Treatment • Screening • Sedimentation • Sludge • Evaporation • Storage • Extraction
Grass Filtration • Soil type • Grass type • Bacteria • Result
Grass Filtration Transpiration Rye Grass In Out Clay soil Concrete drain Earth drain
Land filtration • Soil type • Friable • Grass type • Bacteria • Water evaporation / Transpiration • trees • Grazing • Recycling • Result • Best method
Land filtration Aerobic bacteria Anaerobic Bacteria
Digestion in Aquatic Environments • In stationary water two layers develop: • Upper Layer with the oxygen • oxygen being used up by aerobic and facultative bacteria. • CHO N S ---> CO2 + NO3 + SO4= • The bottom layer • No oxygen so anaerobic bacteria grow. • Digest organic mater ---> H2S, NH3 and CH4. • The bad smelling gases • Don’t escape to the environment • oxidised to H20, NO2-, SO4 and CO2 in the aerobic layer.
Lagoon System • Grass filtration can be saturated if too much water. • Lagoons can vary the though put by over 10 times • The more material put through the lagoons the faster the bacteria grow
Marine Digestion • A marine environment similar to lagoons. • If the affluent is discharges far enough out • BOD removed before any reaches the coast • Affluent must be primary treated. • The massive amount of non-salty water will alter the ecosystem • causing a different organisms to develop.