Waste Water Treatment, St Mary Essay
This report will cover the history, operations and future potential for the St Marys Sewage Treatment Plant and St Mary’s Water Recycling Plant, which located in an industrial area in St Mary’s, a western suburb of Sydney.
A group of subject 48350 Environmental and Sanitation Engineering students visited both plants, and observed the operations and maintenance of these wastewater treatment systems.
1.2 St Marys Sewage Treatment Plant
In 1939, the Sewage Treatment Plant was first commissioned at St Mary where it serviced a government facility nearby using a trickling filter system – obviously a small scale operation.
The Plant was …show more content…
Screening – In order to trap and remove the majority of large solids such as garbage, leaf litter, cigarette butts, tissues/paper, etc in wastewater, two 3mm step screens are used that are cycled in a step motion to allow cleaning of used sections and for fresh sections to continue filtration.
Fig 2 & 3: Filth and accumulated litter on screens.
Aerated grit tanks – the wastewater enters into 3 long tanks (14.3m x 2.7m x 2.5m), where air is added, causing a high speed spinning motion where grit and small particles are forced into a separate channel.
The air is added into wastewater when it enters into 3 long tanks (14.3m x 2.7m x 2.5m), which causes high speed spinning motion where grit and small particles are forced into a separate channel.
Primary clarifiers – after the grit tanks, the water is fed at a rate of 1000L/sec into 6 long but shallow tanks (38m x 7m wide x 3m deep) and moved by a series of slow moving paddles/boards. The remainder of suspended solids are allowed to