Membrane technology couldn't survive poultry wastewater. VelRay X changed that
A superfiltration manufacturer has a membrane technology that can clean challenging protein processing wastewater. What’s prevented the use of this technology is the absence of an upstream filter to pull the solids out first and keep the membrane alive. In an 8-week pilot at a poultry harvesting plant, VelRay X did the upstream job, and the full system returned 97% of the plant's wastewater for reuse.
What protein plants pay for today
A poultry plant runs on water, and most of it leaves carrying solids, fats, oils and grease (FOG). That wastewater hits the budget in four places:
Water that can’t be reused. Intake is high and expensive. Every gallon that goes to drain is a gallon that must be bought again, and a sustainability target that gets harder to hit.
Surcharges. Effluent limits keep tightening, and municipalities bill for every point of BOD, TSS and FOG over the line.
DAF management. Polymer and coagulant on order. Concentrate on a truck. Upsets that stop production without warning, and a crew that clears them by hand.
Skimmings worth less every year. DAF chemicals cut what renderers will pay for them, and forever-chemical rules limit where they can be land-applied.
Why membranes have stayed out of protein processing
Membranes make the effluent quality protein plants need, but using them has been a nonstarter. In protein wastewater, conventional membranes foul past the point of recovery: more cleanings, more chemical, early replacement, more downtime. Most can't tolerate FOG at all.
A global leader in membrane solutions built a superfiltration system that can handle protein wastewater. That left one challenge: suspended solids still had to come out before the water reached the membranes, and no traditional upstream solution could do that in water this greasy.
The plant: doubling the flow, with no room to build
The pilot customer, a poultry harvesting facility, was expanding. Wastewater flow was about to double, to 750,000 gallons per day.
Its treatment train ran feather and meat screens, a secondary screen and an air-only DAF. That setup was already costing money: DAF effluent drew surcharges, system upsets caused unplanned production downtime, and the DAF ran on purchased chemicals whose concentrate had to be hauled off.
Building a second treatment train using standard equipment (equalization tank and a DAF) would require the construction of a new building to house it. That meant the same problems at twice the volume.
The pilot
A VelRay X system was put through an 8-week onsite pilot to tackle five separate waste streams: primary screen effluent, meat screen effluent, DAF effluent, the inside-outside bird washer and the dip tank. The system treated all five.
VelRay X took the place of the air-only DAF, between the secondary screen and the superfiltration skid. It removed suspended solids from water that carried high levels of FOG, which is exactly the feed it was built to handle.
Results
On total plant wastewater, the pilot system recovered 97% of the water for reuse at an operating cost under one cent per gallon. TSS fell 98% and FOG dropped below detection.
Parameter | Raw water | Superfiltration permeate | Discharge limit | Total rejection |
FOG | 88.2 | <4.8 (n.D.) | 50 | 100% (N.D.) |
TSS | 692 | 14 | 250 | 98% |
BOD | 3,050 | 295 | n/a | 90.3% |
TKN | 187 | 54.3 | n/a | 71% |
Source: Superfiltration manufacturer onsite pilot, poultry harvesting facility. Raw water compared with final superfiltration permeate.
The concentrate turned out to be an asset. Samples were submitted to a rendering facility, who came back highly confident it could turn the material into revenue.
The need for a new building came off the table. The entire system fit in a 2,000 square foot space inside an existing facility.
What it's worth at full scale
The superfiltration manufacturer modeled the full system for a 700,000 to 800,000 GPD harvesting facility, the size this plant is growing into. These are projections, not measured pilot results.
Modeled impact | Projected value |
Avoided costs from plant shutdowns | $1M to $2M per year |
Revenue from rendering chemical-free concentrate | $700K to $1.5M |
Avoided hauling costs | $400K to $500K |
DAF chemical savings | $200K to $300K |
Avoided surcharges | $100K to $200K per year |
Footprint | 1,500 to 2,000 sq ft, inside the existing layout |
Source: Superfiltration manufacturer economic model
The implications
For the poultry producer, wastewater stops capping growth. The plant can expand inside the walls it has, buy less water, and dros a chemical-fed DAF that needed constant tending. The waste stream becomes water it reuses and concentrate a renderer wants.
For the superfiltration manufacturer, the missing piece is in place. A membrane built for FOG-heavy wastewater now has a proven pretreatment step in front of it. That provides a way into protein processing, a market they have stayed out of.
Protein wastewater has always been a cost to manage. With the right technology like VelRay X in front of the membrane, it becomes a resource.
