South Gippsland, Victoria, Australia WWTP

  • Client: South Gippsland Water
  • Date: Monday, 07 April 2014
  • Info: Retrofit of Accel-o-Fac System to aerated wwtp cells

South Gippsland, Victoria, Australia WWTP. Accel-o-Fac® wastewater treatment upgrades to South Gippsland Water for implementation at two of their wwtp's located just outside Inverloch, Victoria in South Eastern Australia.

The initial order followed detailed evaluation over a 12 month period by South Gippsland Water culminating in a site visit by one of their Director’s to Anglian Water’s Aero-Fac wwtp at Tipps End in the UK. The order was the first for the Accel-o-Fac® system in Australia.

The Accel-o-Fac® system utilises the SERIES 3 wind-powered aerator/mixer, and is a well proven, sustainable upgrade for existing lagoon-based wastewater treatment systems such as the Inverloch wwtp.

Located on the southern tip of Victoria, the Inverloch wwtp offered South Gippsland Water the opportunity to utilise consistent winds to improve treatment, while keeping energy costs to a minimum and further enhancing their sustainability credentials.

The Accel-o-Fac® system provides wwtp operators with an extremely robust, odour-free system that requires little in the way of operator attention or maintenance, and, best of all, no sludge handling or removal.

South Gippsland Water Utility Company Places Second Order

One year later in April 2015, South Gippsland Water placed a follow-up order with Gurney Environmental to upgrade another of their wastewater treatment plants at Toora using the same Accel-o-Fac system.

Positive Results With First System

South Gippsland Water partially upgraded the Inverloch wwtp with the Accel-o-Fac system in April of 2014. Through routine monitoring of the conditions of the cell since installation, the utility company reported that not only have they benefited from a 16% increase in average DO, but they have also been able to significantly reduce the operation of the existing electric powered aeration system at the plant. This has provided South Gippsland Water with a 22% reduction in overall energy costs, which will pay for the upgrade within a few years of operation.

Positive Results With Second System at Toora

South Gippsland Water upgraded the Toora wwtp with the Accel-o-Fac system in April of 2015. Through routine monitoring of the conditions of the cell since installation, the utility company reported that not only have they benefited from a dramatic increase in average DO, but they have also been able to significantly reduce the operation of the existing electric powered aeration system at the plant. This has provided South Gippsland Water with a 72% reduction in overall energy costs, which will pay for the upgrade within a few years of operation.

Accomplishing maximum BOD removal processing rates in a facultative biological treatment system is dependent on maintaining positive DO at all times. With positive DO conditions, the aerobic bacteria will perform at their maximum for a given water temperature. Additionally, odours can be 100% buffered/stripped by an oxygen-rich water column.

Gurney Environmental completed the installation of the primarily wind-powered Accel-o-Fac® wastewater treatment system upgrade for South Gippsland Water in mid 2015. After a year of operation, managers of the wwtp have provided the results of typical DO profiles now being accomplished with dramatically reduced energy, and the results are impressive. The high residual DO levels being maintained by the Accel-o-Fac system now allow the original electric aeration to be shut off for much of the time through the use of a DO controller.

If a facultative primary treatment cell has a minimum of 1-2 ppm of residual DO, the aerobic bacteria perform waste removal at maximum rates (based on water temperature), as well as 100% odour removal/buffering. Systems are designed to maintain a typical minimum average of 2 ppm. The Toora Accel-o-Fac® mostly wind-powered system has maintained an average of 12 ppm with zero-to-low energy cost. This surplus DO profile would allow the cell to be loaded at an even higher surface rate without affecting performance. 

Since the major provider of DO in a lagoon is photosynthesis, the maximum DO deficit in a facultative primary treatment cell occurs at about dawn. A large amount of DO is consumed overnight but is supplemented by the atmospheric absorption and redistribution provided by the wind-powered aeration units. The Toora Accel-o-Fac® system has been maintaining an average of 4 ppm at dawn with zero-to-low energy cost. This surplus DO profile underscores that the cell could be loaded at an even higher surface rate without affecting performance. 

 

Brett Vurlow of South Gippsland Water had this to say, "Adding the Accel-o-Fac® system to South Gippsland Water treatment cells where traditional surface aeration was previously used allowed the corporation to significantly reduce energy use. The savings in kWh are excellent with one application saving 72% in energy compared to the previous year."

Wind Powered Wastewater Treatment

The Accel-o-Fac system was chosen to upgrade both the Inverloch and Toora plants following a 12 month evaluation of options from around the world. Of particular interest to South Gippsland Water was the ability to use wind as a primary energy source for the Accel-o-Fac system, which is readily available day or night at these locations. (Note: An optional electric backup Motor Kit activated by wind speed is available.)

Equally important to the water company was the reliability of operation and ability to process wastewater — plus control odour. The significant increase in typical dissolved oxygen from the Accel-o-Fac system has done exactly that for each wwtp.