Engineered multi-stage treatment systems for petroleum refinery effluents, addressing oil removal, phenol reduction, sulphide treatment, and COD compliance. From API separation and DAF flotation to biological polishing, we design integrated solutions that meet EPA, EU BREF, and local discharge standards while enabling water reuse.
Treat drilling muds, cuttings wash water and site runoff. Solid-liquid separation and water recycling for drilling operations.
Refinery wastewater treatment including API separators, DAF, advanced biological treatment and polishing for strict discharge.
Oil and gas wastewater treatment for produced water treatment.
Sour water and desalter effluent treatment for petroleum refineries.
Complex Wastewater from Petroleum Refining
Petroleum refineries generate complex wastewater streams containing free and emulsified oil, phenols, sulphides, ammonia, and high concentrations of organic compounds. Our integrated treatment solutions address each contaminant class through proven processes, ensuring compliance with increasingly stringent discharge regulations while maximising water reuse opportunities. Oil separation, sour-water stripping, biological treatment and tertiary polishing are integrated into a single resilient train. Reynolds & Bauhm tune each stage to the refinery’s crude slate and consent so it meets tightening limits while maximising reuse.
Multi-stage oil separation achieving <15 mg/L O&G through API separators, DAF, and coalescing media for discharge compliance.
Specialised biological and chemical processes for phenol removal, achieving <0.5 mg/L to meet strict environmental limits.
Advanced advanced biological treatment systems achieving 90%+ COD removal through MBBR, SBR, or activated sludge processes.
Polishing treatment enabling water recycling for cooling towers, boiler feed, and process applications reducing freshwater demand.
Integrated dewatering of API separator bottoms, DAF float, and biological sludge to reduce disposal requirements by 60-80%.
Discuss your specific requirements with our technical team and receive a tailored proposal for your project.
Contact UsRefinery Wastewater Parameters & Treatment Targets
| Parameter | Typical Influent Range | Treatment Target | Primary Technology |
|---|---|---|---|
| Oil & Grease | 50 – 500 mg/L | < 15 mg/L (discharge) / < 5 mg/L (reuse) | API + DAF |
| COD | 500 – 2,500 mg/L | < 125 mg/L | MBBR / SBR |
| Phenols | 10 – 200 mg/L | < 0.5 mg/L | Biological Treatment |
| Sulphides (as S²-) | 5 – 150 mg/L | < 1 mg/L | SWS + Biological |
| Ammonia-N | 20 – 300 mg/L | < 10 mg/L | Steam Stripping + Nitrification |
| TSS | 50 – 400 mg/L | < 30 mg/L | LAMELLA + Filtration |
| BOD5 | 200 – 1,500 mg/L | < 25 mg/L | Biological Oxidation |
| Temperature | 25 – 60 °C | < 40 °C (biological) | Equalization + Cooling |
Values are representative of combined refinery effluents. Actual performance depends on crude slate, process configuration, and local regulatory requirements.
Meeting Refinery Discharge Requirements Worldwide
Compliance with EPA Effluent Guidelines for Petroleum Refining (40 CFR 419) covering Best Available Technology (BAT) limits for oil, phenol, sulphide, TSS, and ammonia.
Design and operation aligned with the EU Industrial Emissions Directive and Best Available Techniques Reference Document for the Refining of Mineral Oil and Gas.
Marine discharge compliance for coastal and offshore refinery operations in accordance with MARPOL Annex I and MEPC guidelines.
Tailored designs to meet site-specific discharge permits, Water Framework Directive standards, and regional environmental quality standards.
Refinery Wastewater Sources
Treatment of oily wastewater from crude and product storage areas, process units, and equipment drainage systems.
Explore Process RunoffHigh-salinity wastewater from crude oil desalting containing oil, solids, and dissolved salts requiring specialised treatment.
Explore DesalterTreatment of stripped sour water containing ammonia, phenols, and reduced sulphur compounds from amine and sulphur recovery units.
Explore Sour Water StripperHigh-solids wastewater from tank cleaning and bottoms removal with concentrated oil and sludge content.
Explore Tank BottomsTreatment of wastewater from delayed coking and fluid coking units with high phenol and COD concentrations.
Explore CokingTreatment of blowdown and drainage from cooling towers, boilers, and utility systems throughout the refinery.
Explore UtilitiesIntegrated Refinery Wastewater Treatment
Flow and load balancing to handle variable refinery wastewater characteristics and shock loads.
LAMELLA separators remove precipitated solids and chemical floc with high-rate settling.
Products for Refinery Wastewater
High-efficiency oil and solids removal through microbubble flotation for refinery wastewater.
Benefit: 95%+ oil removal
Gravity oil-water separation for free oil removal upstream of secondary treatment processes.
Benefit: Low operating requirement
Moving bed biofilm reactors for high-rate COD and phenol removal in compact footprint.
Benefit: 90%+ COD removal
High-rate solids separation for primary and tertiary clarification in minimal space.
Benefit: 70% smaller footprint
Screw presses and centrifuges for refinery sludge dewatering to minimise disposal requirements.
Benefit: 60-80% efficiency improvement
Automatic backwash filtration for final polishing and protection of downstream equipment.
Benefit: Continuous operation
Why Choose Reynolds & Bauhm
Deep-Dive into Key Treatment Steps
Multi-stage oil removal using API separators, DAF, and coalescing media to achieve discharge compliance.
Explore Oil SeparationMBBR and SBR systems engineered for phenol removal and high COD reduction in refinery effluents.
Explore Biological TreatmentSpecialised handling of sour water stripper bottoms and desalter effluent with high salinity and sulphides.
Explore Sour WaterDewatering and oil recovery from API separator bottoms, DAF float, and biological waste sludge.
Explore Sludge ManagementPolishing systems converting treated effluent into cooling tower makeup and boiler feed pre-treatment.
Explore Water ReuseExplosion-proof equipment and controls certified for safe operation in refinery hazardous zones.
Explore ATEXExplore Other Oil & Gas Solutions
Treatment of formation water from oil and gas wells for discharge or reinjection.
Explore Produced WaterSpecialised treatment for petrochemical manufacturing wastewater streams.
Explore PetrochemicalComprehensive treatment for downstream oil and gas processing facilities.
Explore DownstreamWastewater treatment for pipelines, terminals, and storage facilities.
Explore MidstreamDirectory of international wastewater treatment regulations and equipment compliance standards Organised by country and region.
View PageATEX-certified wastewater treatment equipment for explosive atmospheres in oil, gas and petrochemical facilities.
View PageRefinery wastewater treatment including API separators, DAF, advanced biological treatment and polishing for strict discharge.
View PageEach refinery effluent stream demands a tailored treatment path. Mixing streams without pre-segregation almost always raises Capital expenditure and Operating expenditure.
Post sour-water stripper (SWS) effluent: 5–30 mg/L NH₃, 1–5 mg/L H₂S, phenols 10–100 mg/L. Biological treatment after equalisation; PAC or ozonation for phenol polishing.
Crude desalter water: high TSS (300–2,000 mg/L), salts (5,000–50,000 mg/L TDS), trace metals, mercaptans. API separation → IGF/DAF → biological. Salt content limits reuse.
High COD (1,500–5,000 mg/L), phenols, cyanide, sulphides. Pre-treat with chemical oxidation or steam stripping before biological. Often the rate-limiting stream for the plant biology.
Stormwater commingled with oil-spill drips. Three-stage API + DAF + sand filter. Sized for design rainfall event with overflow to off-spec holding pond.
Side-stream filtration, sometimes lime softening, conditioning for reuse. Discharge stream is high TDS, low BOD — can run separately to reduce biological load.
Oily sludge with 20–60% oil content. Three-phase decanter or centrifuge for oil recovery; solids to disposal or co-processing. Aqueous phase recycled to head of works.
| Stream | Typical COD (mg/L) | Key contaminant | Primary treatment |
|---|---|---|---|
| Stripped sour water | 200–800 | Phenols, residual NH₃ | Bio + PAC/GAC polish |
| Desalter | 500–2,500 | Oil, TSS, salts | API + DAF + bio |
| Coker / FCC | 1,500–5,000 | Phenols, cyanide | Pre-oxidation + bio |
| Process runoff | 100–500 (event) | Free oil, TSS | API + DAF + filter |
| Utility blowdown | 50–200 | TDS, scale inhibitors | Side-stream filter |
| Tank bottoms | 5,000–30,000 | Oily sludge | Decanter centrifuge |
Dedicated pH-correction system design and reagent selection for refinery wastewater streams.
Read MoreAll pH adjustment technologies, reagents and reactor designs.
Read MoreFeedback, feed-forward and cascade control for pH dosing loops.
Read MoreRight pump for acid / caustic / lime dosing duties.
Read MoreStokes’-law sizing, API Publication 421 design methodology, rectangular API / CPI / TPI configurations and refinery-train integration.
Sizing, components, types, materials, codes & compliance — the full engineering reference for gravity oil-water separation.
Read the API Separators PageCompare the three dominant configurations side-by-side — droplet cut-size, footprint, Operating expenditure and best-fit applications.
Compare Separator TypesCFD-verified F-factor for shorter basins, optimised inlet diffusers and reduced civils Capital expenditure.
CFD EngineeringContact our experts to design a system tailored to your refinery requirements.
Our expertise spans multiple industries with sector-specific water treatment solutions.