Baihuipu Treats Petrochemical Wastewater for Reuse
Baihuipu has treated petrochemical wastewater at a refining complex in eastern China, where the water balance had tipped against the plant after a capacity expansion left the cooling towers short of make-up. The treatment and reuse train was commissioned in July and now processes 300 m3/h of spent process and oily wastewater. After equalization, bioaugmented biological treatment and ultrafiltration, more than 70 percent of the flow returns as cooling tower make-up below 10 mg/L oil and 30 mg/L COD, and the remainder meets the discharge consent. The refinery chose reuse over a new raw water intake because the treated stream was closer and the consent left little headroom for more discharge.
Key Features and Benefits
Equalization Before Anything Else
Petrochemical wastewater arrives in pulses: a unit turnaround dumps a slug of concentrated wash water, a tank draw-off sends a hydrocarbon spike, and a quiet shift sends almost clean cooling blowdown. Sending that straight to biology would swing the load past what the bugs tolerate, so a large equalization basin first blends the stream into something the plant can treat steadily. The same selection criteria reappear in Baihuipu Completes FGD Wastewater ZLD Retrofit, which is worth opening alongside this one.
We set out the wider process route in coking wastewater treatment.
Oil and gravity separators sit inside the equalization stage so the free product is skimmed before it reaches the biology. Removing the bulk hydrocarbon up front protects the biomass and keeps the downstream ultrafiltration from loading up on emulsified oil it was never meant to catch. A related discussion worth reading here is Baihuipu Launches Remote Monitoring Platform for Plants.
Bioaugmented Biology for the Recalcitrant Fraction
Refinery water carries phenolics, sulphides and light aromatics that ordinary biomass handles slowly, so the biological stage was seeded with a culture selected for those compounds and fed a steady, blended feed from equalization. The augmented culture holds degradation rates through the load swings that would stall a generic seed. We have written about the downstream implications separately in Baihuipu Supplies Sidestream Filtration for Cooling Circuits system.
Anoxic and aerobic zones are arranged so the easy carbon drives denitrification while the refractory fraction meets the aerobic culture, which keeps both nitrogen and COD moving without a separate polishing pond. Online respirometry during commissioning confirmed the culture was earning its keep against a plain seed.
Ultrafiltration to Make the Water Reusable
Cooling make-up will not tolerate suspended solids or oil that feeds microbial growth in the tower basin, so an ultrafiltration stage after biology strips the water to a few NTU and low oil before it enters the reuse line. The UF permeate is clean enough that the cooling side dropped its sidestream filtration load.
The UF is run with periodic backwash and a monthly CIP, and the reject returns to equalization rather than being wasted. The refinery meters the reuse flow against evaporation so the water balance is checked weekly, not assumed.
Technical Specifications
Water quality at key points of the petrochemical reuse train:
| Parameter | Raw Wastewater | Reuse Make-up |
|---|---|---|
| Oil and grease | 50 to 200 mg/L | below 10 mg/L |
| COD | 400 to 900 mg/L | below 30 mg/L |
| Suspended solids | high | below 5 mg/L after UF |
| Turbidity | cloudy | below 2 NTU |
| Reuse rate | baseline | above 70 percent of flow |
Why Choose Baihuipu as Your Manufacturer
Two decades in this industry teaches you that most treatment problems are procurement problems in disguise. Someone bought the cheapest skid, nobody checked the equalisation volume, and eighteen months on the plant cannot hold its consent limit. We build differently.
Own Factory, Real Capacity
Tanks, skids, control panels and membrane housings are built in our own Guangdong facility. Nothing critical is subcontracted, which is why we can commit to delivery dates and hold quality across a batch instead of hoping the shop floor gets it right.
20+ Years Across Dozens of Industries
Experience matters most when your waste stream behaves nothing like the textbook example. We have dealt with toxic organics, heavy metals, extreme salinity and refractory COD in food processing, chemical manufacturing, electroplating, mining and municipal projects.
Complete System Responsibility
One supplier, one process guarantee. We take the plant from preliminary screening through to membrane separation, evaporation and brine management, with process, mechanical, electrical and controls engineering handled internally.
Spares, Service and Commissioning
Membranes, dosing pumps, diffusers, instrumentation and blowers are stocked for the systems we sell. Our control systems support remote diagnostics, and we can put an engineer on site for commissioning, training or an unplanned shutdown.
Twenty-Plus Export Markets
We have shipped to the United States, Canada, Russia, Indonesia, India, Nigeria and Vietnam among others. Crating, export documentation and certificates are handled in-house, which keeps customs surprises to a minimum.
Let's Look at Your Numbers
Share your water analysis and site constraints and we will give you a straight assessment of the process route and the realistic operating cost before you commit to anything. Contact our engineers at WhatsApp: +86 13631765076, or find us at hkbhp.com.
WhatsApp: +86 13631765076
Customer FAQs
What makes petrochemical wastewater hard to treat?
The mix of free and emulsified oil, phenolics, sulphides and light aromatics arrives in pulses and is toxic to ordinary biomass at concentration. Equalization, oil separation and a culture selected for those compounds are what make the biological stage stable.
Can petrochemical wastewater be reused directly?
Only after it is treated to the reuse standard. This plant returns ultrafiltered water as cooling make-up below 10 mg/L oil and 30 mg/L COD; the rest meets discharge. Reuse also avoids the cost and consent limits of drawing more raw water.
Why not just discharge everything?
The site consent left little headroom after expansion, and a new raw water intake was both slower and more expensive than treating the spent water on site. Reuse closed the cooling water gap without adding discharge load.
How is the biological seed kept effective?
By feeding it a blended, equalized stream and monitoring respiration response, plus periodic culture top-ups when the feed profile shifts. The culture was selected for refinery compounds rather than a generic municipal seed. The operating detail behind this sits in dye printing wastewater decolorization.
Readers planning similar projects often also read Baihuipu Launches Containerized Seawater Desalination Plant for the process detail behind these systems.
