Melbourne Sewage System

1. Melbourne Sewage System Western Treatment plant Eastern treatment Plant Regional treatment plans

2. Western Treatment plant • Primary Treatment • Sludge • Grass Filtration • Land Filtration • Lagooning • Aerobic • Facultative

3. Primary Treatment • Screening • Sedimentation • Sludge • Evaporation • Storage • Extraction

4. Grass Filtration • Soil type • Grass type • Bacteria • Result

5. Grass Filtration Transpiration Rye Grass In Out Clay soil Concrete drain Earth drain

6. Land filtration • Soil type • Friable • Grass type • Bacteria • Water evaporation / Transpiration • trees • Grazing • Recycling • Result • Best method

7. Land filtration Aerobic bacteria Anaerobic Bacteria

8. Lagooning

9. 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.

10. Digestion In a Pond

11. Dissolved Gases In Pond

12. Lagoon System

13. 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

14. Throughput in a Lagoon

15. Serpentine Lagoons

16. Lagoon at Werribee

17. Capture of Methane

18. Marine Disposal

19. 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.

20. The End