Oil refinery wastewater is a challenging mix of hydrocarbons, phenols, ammonia, sulfides and oil and grease. It requires effective oil and sulfide management upstream, after which MBBR provides combined biological treatment: degradation of biodegradable organics including phenols, and nitrification of the ammonia load. The fixed biofilm gives the stability needed for a continuous, high-value process.
A Combined Carbon and Nitrogen Duty
Oil is removed upstream by API separators and dissolved air flotation, and sulfides are managed to protect the biology and control odour. An acclimated biofilm degrades phenols and other biodegradable organics, while the ammonia load calls for nitrification — often in a later stage where the carbon load has fallen enough for nitrifiers to establish. Staging the MBBR lets carbon removal and nitrification each develop the biofilm they need.
Because refinery effluent contains inhibitory and recalcitrant fractions, treatability testing is used to confirm the achievable performance and any polishing required.
Refinery Wastewater Design Context (site-specific — confirm per project)
| Parameter | Typical Value | Unit | Notes |
|---|---|---|---|
| Key constituents | hydrocarbons, phenols, NH₄-N, sulfides | — | Plus oil & grease |
| Oil & sulfide | manage upstream | — | API separator + DAF |
| Carbon | acclimated biofilm | — | Degrades phenols |
| Nitrogen | nitrification | — | Staged after carbon removal |
Stability for a Continuous Process
Refineries run continuously and value treatment that stays stable through upsets. The retained biofilm of an MBBR provides that resilience, which — with staged carbon and nitrogen treatment — makes it a common choice for refinery effluent, closely related to petrochemical duty.
Frequently Asked Questions
What makes refinery wastewater difficult?
Can MBBR nitrify refinery ammonia?
How are phenols handled?
Related Pages
Need MBBR Design Support?
Submit your wastewater data for a preliminary MBBR engineering assessment. Our team reviews every submission within 2 business days.