video-banner
none

VENTURI AERATOR IMPROVES WATER TREATMENT FOR BEGA CHEESE

16-09-2019
by 
in 

In 2018, Bega Cheese Environmental Manager – Northern Victoria, Sean Trebley was given the task of upgrading the wastewater aeration system at the company’s Strathmerton plant.

The wastewater system consisted of a dissolved air flotation (DAF) unit, which flowed into an aerated lagoon, and after this the effluent was stored in two non-aerated lagoons during winter, before irrigation in summer.

Aerators are needed to keep the chemical oxygen demand (COD) down and reduce odours in both the aerated lagoon and the downstream non-aerated lagoons.

The company had an ageing system of surface aerators in the aerated lagoon, consisting of two 22kW units and six 8kW units. However, generally only one or two of these units were operated at any given 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 uneconomical to keep on repairing the aerators. So Bega Cheese decided to look for a solution that was safer for operators and easier to maintain.

Sean Trebley contacted Hydro Innovations to discuss the application of “bank-mounted” Venturi Aeration systems. These systems are mounted on the banks of lagoons and use a self-priming pump to draw water from the lagoon. The pump discharges it under pressure through the venturi aerator.

The unit draws in atmospheric air using the “venturi effect”, mixes it with the water being pumped, and discharges it back into the lagoon, charged with dissolved oxygen.

Trebley and his team liked the idea of bank-mounting because it gave operators easy access to equipment for monitoring and/or repair, making it much safer and more cost effective to maintain. Their only concern was whether the units were as efficient as the surface-mounted technologies.

Hydro Innovations was able to provide information indicating that with the use of the right pump, oxygen transfer efficiency for Venturi Aeration units can be as high or higher than 1.86kgO2/kWh, making them as at least as efficient as the surface (floating) technologies.

The aerated lagoon contained 45ML of effluent, with in-flows from 80 to 120ML per year. This required a 150mm Venturi Aeration unit and was paired with a Gorman-Rupp V6A60-B self-priming pump, with a hydraulic efficiency of 70%.

Bega Cheese installed the unit early in 2019.

Before installation: The condition of the lagoon after the previous system had been decommissioned several months before.

After installation: Two weeks on, and it can be seen that ripples from the 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 resuspending settled solids, which became more “bioavailable” to the colony-forming units.

Sean Trebley and the Bega Cheese crew are happy with the ever-increasing levels of DO, the reduction in COD, and their odour-free lagoon. The wastewater and 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 Aeration venturi aerators and Gorman-Rupp pumps can be obtained from Hydro Innovations.

Hydro Innovations
02 9898 1800
www.hydroinnovations.com.au

 

Related news & editorials

  1. 17.10.2019
    17.10.2019
    by      In
    With OH&S issues being a priority for all companies, the range of pumps distributed by Hydro Innovations addresses both operator safety and pump maintenance costs, while delivering improved performance in waste management.
    The need to access wet wells with multiple people to repair submersible... Read More
  2. 06.10.2019
    06.10.2019
    by      In
    SPX Flow has appointed of Assett Mechanical Engineering (also known as AME Pump Specialists) as its new channel partner in South Australia for its APV and Waukesha Cherry-Burrell (WCB) product lines.
    Founded in 1981, AME has long served the South Australia region with an excellent reputation for... Read More
  3. 11.07.2019
    11.07.2019
    by      In
    The basic principle of the peristaltic pump traces back to human “peristalsis” (a term referring to the alternating contraction and relaxation of muscles around a tube to force the contents through it).
    An elastomeric tube is squeezed along its length by rollers or shoes that pushes the fluid... Read More
  4. 21.05.2019
    21.05.2019
    by      In
    A chance meeting in the car park at the 2018 Water Industry Operators Association (WIOA) Conference in Tamworth has led to a successful change of peristaltic pumps at the Bathurst Water Treatment Plant.
    The encounter was between WIOA Operator of the Year David Cashen and Phil Rothheudt, NSW... Read More