California chicken kill plant protects expensive downstream processes

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A large California chicken kill plant had a secondary drum screen that was failing to adequately protect their Equalization Basin (EQ).

As a result, Dissolved Air Flotation (DAF) and Biological Nutrient Removal (BNR) systems were unable to operate effectively, placing the plant in breach of local regulations.

Plant operators indicated that their EQ tank was about 70% filled with solids. The solids load had become so bad, in fact, that they were no longer able to operate mixing equipment in the EQ tank.


A Hydro-Industrial MicroScreen™ rotating belt screen was installed downstream of the drum screen to capture materials that were passing through it.


After just 24 hours, the Hydro-Industrial MicroScreen™ removed 2,000 lbs (900 kg) of material, at 32% dry solids, that would otherwise have been free to enter downstream treatment processes and rapidly fill their EQ tank.

Under full, continuous operation the Hydro MicroScreen™ system prevented 7,600 lbs (3,400 kg) of solids from entering other wastewater treatment processes every day.

Fats, oil and grease (FOG) levels were also measured. FOG loading varied widely depending on when sampling was conducted—at one sample point, the plant had as much as 1.6 ounces (4.5 g) of FOG in each litre of water—yet the Hydro MicroScreen™ system was able to remove an average of 83% of the FOG as an added benefit before entering the EQ basin.

Additionally, the output from the Hydro-Industrial MicroScreen™ was 32% Total Solids (TS), providing dry material that was much more cost-effective to dispose of, and which increased profits on reselling / repurposing of otherwise wasted by-product.

Despite being placed after a drum screen, it is estimated that the Hydro-Industrial MicroScreen™ will prevent 1,387 tons of by-product from entering expensive downstream treatment processes each year.

Full ROI was calculated at 1 year from solids reduction alone.