FAST wastewater treatment for purification and recycling

The FAST® (Fixed Activated Sludge Treatment) was completely supplied and installed by CST Wastewater Solutions at the CVO site in NSW.
The treatment system, representing the latest generation of Smith & Loveless FAST technology, is part of CVO’s ongoing program to maximise community benefits flowing from a project that will include Australia’s largest underground mine and the world’s fourth largest gold mine.
“This is a proven environmental initiative by Cadia that demonstrates its concern to optimise conservation of water as a resourced shared with the broader community,” said CST Waste Water Solutions managing director Michael Bambridge.
“Cadia is taking a lead as mining companies throughout Australia face the same challenge of optimising water resources as they expand their operations and job opportunities to the benefit of  surrounding communities.”
The FAST system is applicable to many unsewered situations including mine and resource developments – where it has been proven for 20 years – as well as construction sites, wineries, hotels and resorts, schools, shopping centers, caravan parks, sports and leisure centers, and boat marinas.
The easily transportable FAST system, which can be built into shipping containers, is designed to handle 40-120 cubic metres/day of sewage and other effluent from the mine. It will produce an effluent quality of:
BOD < 20 mg/l
SS < 30 mg/l
Faecal Coliforms < 1000 cfv/100 ml to meet NWQMS guidelines for secondary effluent plus pathogen reduction.
“A big plus of Smith and Loveless FAST systems is that they are very robust and reliable in service, having been supplied to the resources industry for more than 30 years,” said Bambridge.
“They are simple to operate and require no daily operator maintenance, so annual maintenance costs are low.
“Treated effluent wastewater from the resource plants can be mixed with mine and runoff water and sprayed on the mine’s haul roads for dust suppression, for example.”

Technical process
Unlike conventional suspended growth systems, bacteria grow rapidly on the media while the liquid that evenly circulates through the media is essentially clear, with low solids levels.
As the bacteria grow and increase in thickness, the film strength of the bacterial growth weakens and a sloughing of surface solids occurs. The microbes’ anaerobic action results in continuing reduction in cell mass and a reduced biological sludge accumulation to be removed from the bottom of the clarifier. This lessens the required area for tankage and associated equipment.
Typically, an extended aeration plant has a mixed liquor suspended solids level (MLSS) of 3000-4000 milligrams per litre. At this level the clarifier is being operated at close to the maximum solids flux (sludge accumulation).
With the FAST treatment system, on the other hand, the bacteria grow on the submerged media, and the mixed liquor circulating through the bacteria-laden media is essentially clear and free of suspended solids.
This reduces the MLSS flow to the clarifier to approximately 100-400 mg/L and greatly reduces the amount of solids flux, which means less stress on the clarifier.

For further information, please contact tel: 61 (0)2 9427 1279; email: info@cstechnology.com.au; or visit: www.cstwastewater.com