Advanced DAF Treatment Enables Efficient Wastewater Management at a Renewable Diesel Refinery
- May 18
- 3 min read
Updated: May 19
As renewable diesel production continues to expand across North America, operators face a familiar challenge: how to effectively manage wastewater streams with extremely high oil, grease, and solids loading. One renewable diesel refinery processing recycled animal fats and used cooking oils turned to FRC Systems for a reliable, chemical‑physical wastewater solution designed to meet strict discharge limits while recovering valuable oils.
This case study highlights how a properly engineered dissolved air flotation (DAF) system helped the facility achieve consistent compliance, operational reliability, and improved oil recovery.
The Challenge:
High‑Strength Wastewater from Renewable Feedstocks
The refinery operates at approximately 10,000 barrels per day, converting recycled fats, oils, and greases into renewable diesel fuel. While these feedstocks support sustainability goals, they also generate wastewater with exceptionally high contaminant concentrations.
Influent wastewater characteristics included:
Flow rate of 80,000 gallons per day
Total Suspended Solids (TSS): 9,700 mg/L
Fats, Oils, and Grease (FOG): 7,400 mg/L
The wastewater originated from both Accidental Oil Containment (AOC) and Continuous Oil Containment (COC) areas across the site. Without effective treatment, these streams posed a risk to downstream processes and regulatory compliance.
Treatment Objectives
The refinery required a treatment system capable of:
Consistently meeting discharge limits of 300 mg/L TSS and 100 mg/L FOG
Handling variable oil loading without process upsets
Maximizing oil recovery for reuse or disposal
Operating reliably in an industrial Oil & Gas environment
To meet these objectives, the system needed to be robust, flexible, and engineered specifically for high‑FOG industrial wastewater.
The Solution:
Chemical‑Physical Treatment with FRC DAF Technology
FRC Systems designed and supplied a chemical‑physical wastewater treatment system centered around a high‑performance DAF unit.
Key Equipment Supplied
Integrated chemical dosing equipment
Pneumatic and electrical control systems
Equalization (EQ) tank upstream of treatment
This configuration allowed for optimal coagulation, flocculation, and flotation of oils and suspended solids prior to discharge.
How the DAF Process Works
The treatment process begins with wastewater entering an equalization tank, where flow and loading are stabilized. Coagulants and polymers are then added, promoting the formation of larger, more floatable floc particles.
Within the PWL‑15 DAF, dissolved air is released as microbubbles that attach to oils and solids, lifting them to the surface for removal. The clarified effluent exits the system while concentrated float is skimmed for oil recovery.
Design Highlights
Hydraulic surface loading rate designed at 1 gpm/ft²
Solids loading rate of 5 lb/ft²/hr
DAF sizing based on both hydraulic and solids loading to ensure stable operation
These design parameters ensure the system can handle peak loadings while maintaining consistent effluent quality.
Results:
Reliable Compliance and Oil Recovery
Following installation, the FRC DAF system successfully reduced influent contaminants to within required discharge limits:
Parameter | Influent | Discharge Requirement |
Flow | 80,000 gpd | — |
TSS | 9,700 mg/L | 300 mg/L |
FOG | 7,400 mg/L | 100 mg/L |
In addition to regulatory compliance, the refinery benefited from:
Improved operational stability
Efficient removal of free and emulsified oils
Recovery of skimmed oil for proper handling
Reduced burden on downstream treatment systems
Why This Matters for Renewable Fuel Producers
As renewable diesel and biofuel facilities continue to scale, wastewater treatment systems must evolve alongside production demands. High‑FOG waste streams require more than generic treatment solutions—they demand purpose‑built DAF systems engineered for industrial performance.
This project demonstrates how FRC Systems combines process expertise, proven equipment, and application‑specific design to help Oil & Gas and renewable fuel producers protect infrastructure, meet environmental requirements, and operate with confidence.
Looking for a Similar Solution?
If your facility is struggling with high‑oil wastewater from refining, food processing, or industrial operations, an FRC DAF system may be the right fit.
Contact FRC Systems to discuss your application and learn how customized flotation solutions can transform your wastewater challenges into operational success.
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