Attachment 3B - Process Design Strategy - OREZ · 132005.638.06

PR25001 Noosa Composting Facility
Process Design Strategy




2.2.     Green Organic (GO) Waste & Source Separated Food Organic
         (FO) Waste Pre-treatment
GO Waste Pre-treatment:

Incoming green organic waste feedstock is stockpiled in a dedicated storage bunker and
fed to a shredder for size reduction. The shredded material is then conveyed beneath an
over band ferrous magnet, which removes ferrous metal contamination, and into an
intermediate storage bunker ahead of the IVC tunnels. This intermediate bunker is sized to
hold approximately half of one tunnel volume, providing buffer storage between pre-
treatment and tunnel loading.

FO Waste Pre-treatment:

Source separated FO is delivered by the collection vehicle and, where the source is vetted
and proven reliable, is tipped directly into the receival hopper by the delivery vehicle. The
hopper lid is opened for unloading and closed immediately afterwards. This is expected to
be the normal mode of operation for the majority of deliveries.

Where a source is new or not yet proven, the delivery is instead directed to the push wall
bay, which keeps food deliveries isolated so that NSC operational personnel can inspect the
load and confirm contamination is within acceptable limits before the front-end loader
operator transfers the discrete FO into the hopper. Once a source has been vetted over
several deliveries, it reverts to direct tipping into the hopper by the delivery vehicle.

To limit both the time discrete FO is held and its odour potential, the FO is blended with GO
through the shredder, held in an intermediate bunker, and moved into the process as
promptly as practicable.

The food waste bunker is to be sized to minimise the frequency at which it is emptied into the
intermediate bunker, and so to minimise the time that FO mixed with GO is held in the
intermediate bunker awaiting tunnel availability. The design intent is that blended material
moves into the composting process as efficiently as possible and is not left exposed for any
longer than necessary. Bunker sizing is nonetheless to remain practicable, balancing
operability against capital cost, and is to be confirmed with the tunnel filling schedule.

The receival hopper is a sealed vessel fitted with a hydraulic lid that remains closed except
during unloading. Material is transferred from the hopper by an enclosed screw conveyor to
the shredder, where it is fed simultaneously with green organics so that blending occurs
entirely within the shredding step. There is no subsequent mixing of food waste in the open
processing area.

Extracted air from the receival hopper and the enclosed screw conveyor is directed to the
same air handling and biofilter system that serves the IVC tunnels.

During periods with no FO deliveries, the hopper lid remains closed, and air is extracted from
the hopper.




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