In 2018, the Environmental Manager at Bega, Northern Victoria, Mr Sean Trebley, was given the task of upgrading their Strathmerton Plant’s wastewater aeration system.
The wastewater system consisted of a DAF unit, which flowed into an aerated lagoon, and after this the effluent was stored in 2 non-aerated lagoons during winter, before irrigation in summer.
Aerators are needed to keep the COD down and reduce odours in the aerated and the downstream non-aerated lagoons. They had an ageing system of surface aerators in the aerated lagoon, consisting of two 22kW units and six 8kW units, however generally only 1 or 2 of these units were operated at any time.
Over a number of years these surface aerators had progressively failed because of their age and repairing them meant deploying cranes and/or boats to access them. This process was expensive and had resulted in damage to the dam liner. Eventually it became uneconomic to keep repairing the aerators.
Therefore it was decided to look for a solution that was safer for operators and easier to maintain.
The Bega crew are very happy with the results! The wastewater and maintenance teams are pleased that monitoring and maintenance can be done safely.
The Solution
A 150mm Venturi Aerator and a Gorman-Rupp V6A60-B self-priming pump was installed in early 2019.
The above photo shows the condition of the lagoon before the Venturi Aerator was installed and operating.
The after photo shows the amazing transformation of the lagoon.
In this photo, it can be seen that ripples from the Venturi aerator “radiate” to all parts of the lagoon, ensuring a good level of mixing.
Since installation, operators have seen a continued increase in the dissolved oxygen [DO] level, and have seen COD fall by 50% even though the higher level of mixing was re-suspending settled solids, which became more “bioavailable” to the CFUs.
Sean and the Bega crew are happy with the ever-increasing levels of DO, the reduction in COD, and their odour-free lagoon. The Wastewater & Maintenance Teams are also pleased that monitoring and maintenance can be done safely, and without the use of cranes, boats or winches.
More information about Venturi Aerators or Gorman-Rupp pumps can be obtained from info@hydroinnovations.com.au
The Pumps
The Gorman-Rupp Ultra V Series is the most advanced self-priming centrifugal wastewater and sewage pump range on the market today. They are high performance, high head, and high-efficiency pumps, designed to deliver a long and low maintenance service life, with low cost of ownership.
The Venturi Aerator features a classic design for modern applications. Whether you need a complete replacement or simply an enhancement to your existing system, the Venturi Aerator offers an innovative and convenient approach to your aeration needs.