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

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

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

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

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

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

7. Land filtration Aerobic bacteria Anaerobic Bacteria

8. Lagooning

9. Digestion in Aquatic Environments n In stationary water two layers develop: – Upper Layer with the oxygen –oxygen being used up by aerobic and facultative bacteria. n CHO N S ---> CO 2 + NO 3 + SO 4 = n The bottom layer –No oxygen so anaerobic bacteria grow. –Digest organic mater ---> H2S, NH3 and CH4. –The bad smelling gases n Don’t escape to the environment n oxidised to H20, NO2-, SO4 and CO2 in the aerobic layer. n 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. n Grass filtration can be saturated if too much water. n Lagoons can vary the though put by over 10 times n 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 n A marine environment similar to lagoons. n If the affluent is discharges far enough out n BOD removed before any reaches the coast n Affluent must be primary treated. n The massive amount of non-salty water will alter the ecosystem n causing a different organisms to develop.