Aviation - Maintenance/Repair/Overhaul (MRO) of Corrosion
Army Aviation Centre, Oakey, Queensland, Australia
The AdTech Wastewater Treatment Plant at the Oakey Army Aviation Centre was commissioned in August 1993. It successfully treated over 6 million litres of toxic waste on a batch basis between August 1993 and March 2009.
The source of the effluent on this base is the Corrosion Control facility, where fixed wing aircraft and helicopters are regularly 'de-painted' and 're-painted'. This facility is operated for Defence by Boeing. Many of the Army's latest Tiger helicopters are prepared and painted at AACO. Paint shop waste is also brought in from Amberley RAAF Base (also operated by Boeing), for treatment by AdTech.
As paint is stripped from the aircraft, the contaminated effluent drains to a 20,000 litre capacity settling tank, pouring over a mesh grid to separate gross solids. That tank in turn overflows to a 50,000 litre dirty water storage tank. The effluent within is contaminated with Phenols, Methyl Ethyl Ketone (MEK), Dichloromethane (DCM) and Chromates.
A submersible pump transfers the liquid waste to the AdTech reaction tanks (2 x 18,000 litre capacity, specially lined concrete tanks), where chemical oxidation, reduction and clarification all take place.
Once settled, the clarified water is pumped to the AdTech Megasorbers for final polishing through our patented filtration/adsorption process. This unit has a nominal operating capacity of 6,000 litres per hour in "series" configuration. This can be increased to a nominal flow of 12,000 litres per hour when treating specific effluents by switching over to parallel configuration.
The Megasorption process is ideally suited to Oakey, an area prone to drought. The final process results in a liquid so clean and clear it is recycled and re-used. After Megasorption, the treated water is pumped to a 50,000 litre capacity clean water holding tank and from there, recycled back to the paint shop for further use.
When treated water from the AdTech plant is surplus to paint shop requirements, it is used to irrigate grassed areas on the base (currently operating under Level 5 water restrictions). Defence has recently installed pipework for the excess treated water to add to the Base's bore water irrigation scheme. Furthermore, a new pipeline now runs from a retention pit holding contaminated stormwater directly to the AdTech treatment plant, effectively 'doubling' the volume of water recycled on base each year.
All wastewater generated by Oakey's corrosion control and paint shop operations (plus additional wastewater from the other sources mentioned), are treated on-site by AdTech. The cost of this treatment is a fraction of what would be spent for off-site disposal, with savings to Defence so far running into millions of dollars.