Page 11 - National Poultry Newspaper

Food processing company
gets amazing results with
new venturi-aerator
IN 2018, Bega Cheese Northern Victoria envi- ronmental manager Mr Sean Trebley was given the task of upgrading the Strathmerton Plant’s wastewater aeration sys- tem.
The wastewater system consisted of a DAF unit, which flowed into an aer- ated lagoon, and after this the effluent was stored in two non-aerated lagoons during winter before ir- rigation in summer.
Aerators are needed to keep the COD down and reduce odours in the aerated and downstream non-aerated lagoons.
They had an ageing sys- tem 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 was operated at any time.
Over a number of years these surface aerators had progressively failed be- cause of their age and repairing them meant deploying cranes and/or boats to access them.
This process was ex- pensive and had resulted in damage to the dam liner.
Eventually it became uneconomical to keep re- pairing the aerators.
Therefore it was de-
cided to look for a solu- tion that was safer for operators and easier to maintain.
Mr Trebley contacted Hydro Innovations to discuss the use of their ‘bank-mounted’ venturi- aeration systems.
These 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 at- mospheric air using the ‘venturi effect’, mixes it with the water being pumped and discharges it back into the lagoon, charged with dissolved oxygen.
Sean and his team real- ly 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 informa- tion indicating that with the use of the right pump, oxygen transfer efficien- cy for venturi-aeration units can be as high or
higher than 1.86kgO2/ kWh, making them at least as efficient as the surface (floating) tech- nologies.
The aerated lagoon con- tained 45ML of effluent, with in-flows from 80- 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 percent.
Bega installed the unit early in 2019.
The attached photo shows the condition of the lagoon at this point, after the previous sys- tem had been decommis- sioned several months previous.
In this photo you can see ripples from the aera- tor ‘radiate’ to all parts of the lagoon, ensuring a good level of mixing.
Since installation, op- erators have seen a con- tinued increase in the dis- solved oxygen level and have seen COD fall by 50 percent, 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 the odour-free lagoon.
The wastewater and maintenance teams are also pleased that moni- toring and maintenance can be done safely, and without the use of cranes, boats or winches.
More information about venturi-aerators and Gor- man-Rupp pumps can be obtained from info@hy droinnovations.com.au
Prior to the installation.
US poultry, egg
industries welcome
announcement of
Japan trade agreement
US poultry and egg organisations wel- comed the announce- ment of a trade agreement between the US and Japan.
The USA Poultry & Egg Export Coun- cil, National Chicken Council, National Turkey Federation and United Egg Producers said in a joint state- ment: “frozen chick- en, turkey and pro- cessed egg products will receive favour- able tariff reductions enabling our products to compete more ef- fectively with those of countries in the Trans-Pacific Partner- ship.”
“While this is just
the first stage of a bi- lateral agreement, it is welcome news and we would like to thank President Trump, Secretary Perdue and Secretary Lighthizer for their work negoti- ating trade deals that stand to benefit US poultry and egg prod- ucts.”
Japan is the lead- ing market for US egg product exports, and the second-largest market for US turkey exports.
Japan is also a very promising market for US chicken compa- nies willing to provide the specific chicken cuts Japanese buyers are seeking.
Bega Strathmerton’s new venturi-aerator system.
www.poultrynews.com.au
National Poultry Newspaper, October 2019 – Page 11
Two weeks after the new system was installed.