🏭 Downstream Oil & Gas
Petrochemical & Refinery Waste Water Treatment
From turnaround wastewater surges to spent caustic treatment, boiler feed water purification, and tank cleaning — WFS delivers solutions for every downstream water challenge.
Sector Overview
Built for the toughest streams in the plant
From crude desalting and FCC to ethylene crackers and aromatics complexes, every unit contributes a distinct water stream. Free and emulsified oil, phenols, sulfides, ammonia, BTEX, spent caustic, suspended solids and dissolved salts each demand a different treatment mechanism — and the streams vary continuously with feed slate, throughput and turnaround cycles.
WFS approaches each as an engineering problem: characterize the water, select the right unit operations, and assemble them into a custom train that reliably meets the discharge, reuse or zero-liquid-discharge objective. The same team then fabricates, constructs, automates and operates the plant.
downstream service categories
- Wastewater treatment plants (primary / secondary / tertiary)
- Process & boiler feed water treatment
- Turnaround, spent caustic & VOC treatment
- Olefins & aromatics unit wastewater
- Cooling water, oil-in-water & TSS removal
- Desalination & zero liquid discharge
Typical refinery / petrochemical streams
| Stream | Key contaminants |
|---|---|
| Oily water sewer | Free / emulsified oil, TSS |
| Sour / stripped water | Ammonia, sulfides, phenols |
| Spent caustic | Sulfides, COD, phenolics |
| Cracker quench water | Hydrocarbons, green oil |
| Aromatics condensate | BTEX, solvents |
| Desalter brine | Oil, TDS, solids |
| Cooling blowdown | Hardness, TDS, biocides |
Applications
13 specialized downstream applications
Each opens a dedicated landing page covering process, parameters, challenges, solutions, performance targets, filtration approach, system specification, layout and deliverables.
Wastewater Treatment Plant
Complete primary, secondary and tertiary treatment trains that take combined refinery and petrochemical effluent to discharge, reuse or zero-liquid-discharge quality.
View application
Process Water Treatment
Purification of raw, well or municipal water into high-quality process water for reaction, washing, quench, dilution and utility duties across the plant.
View application
Turnaround Wastewater Treatment
Rapidly deployable mobile and modular treatment for the high-volume, high-strength wastewater generated during plant turnarounds, shutdowns and maintenance.
View application
Ammonia Removal
Targeted removal of ammonia from wastewater, process water and groundwater using stripping, biological nitrification and ion exchange to meet strict nitrogen limits.
View application
Spent Caustic Treatment
Treatment and neutralization of sulfidic, naphthenic and cresylic spent caustic streams using oxidation, stripping and recovery to make them safe for downstream handling.
View application
VOC Removal from Wastewater
Removal of benzene, toluene, xylene and other volatile organics from wastewater using air stripping, steam stripping and activated carbon with full vapor control.
View application
Olefins Unit Wastewater Treatment
Treatment of quench water, dilution-steam blowdown and caustic wash effluent from ethylene / olefins plants, rich in hydrocarbons, oxygenates and spent caustic.
View application
Aromatics Unit Wastewater Treatment
Treatment of BTX / aromatics complex wastewater laden with benzene, toluene, xylene, solvents and oily condensate to meet strict benzene and COD limits.
View application
Boiler Feed Water Treatment
Production of high-purity, low-hardness, low-silica boiler feed water through softening, demineralization, RO/EDI and deaeration to protect boilers and steam systems.
View application
Cooling Water Treatment
Side-stream filtration, make-up treatment and chemical programs that control scaling, corrosion, fouling and microbiology in open recirculating cooling systems.
View application
Oil in Water Treatment
Removal of free, dispersed and emulsified oil from refinery and petrochemical water using API/CPI separation, flotation, coalescence and membrane polishing.
View application
Solids / TSS Removal from Wastewater
Clarification, flotation and filtration systems that strip suspended solids, turbidity and silt from process and waste streams to protect downstream units.
View application
Desalination / TDS Removal
Reverse osmosis, EDR and thermal/ZLD systems that remove dissolved salts from wastewater and process water for reuse, discharge or zero liquid discharge.
View application24 total applications across upstream, midstream & downstream.
Project Lifecycle
One team, concept to O&M
- 01
Study & Assess
We study each application, the unit operations and the discharge or reuse objective.
- 02
Characterize Water
Full laboratory characterization of every stream — flow, contaminants and variability.
- 03
Custom Design
A treatment train custom-designed for the specific water and target specification.
- 04
Pilot & Trial
On-site pilot and trial of the proposed train to de-risk performance, where required.
- 05
Detailed Engineering
PFDs, P&IDs, hydraulic profiles, 3D models and full detailed engineering.
- 06
Equipment Design
Mechanical design of every package and skid in the treatment train.
- 07
Fabricate
In-house and partner fabrication, factory acceptance testing and quality control.
- 08
Deliver to Site
Logistics and delivery of skids, vessels and modules to site, worldwide.
- 09
Construct
Civil, mechanical and piping construction of the complete treatment plant with all connections.
- 10
Electrical & Automation
Electrical connections, instrumentation, controls and PLC/SCADA integration.
- 11
Continuous O&M
Long-term operation and maintenance of the plant with WFS crews and remote support.
Have a Specific Water Challenge?
Submit your water analysis data and our engineers will recommend the optimal treatment approach.