In-Depth Breakdown: How the Three-Stage Synergy of CDFU Cyclonic DAF + JuJie Coalescing Oil Remover + CDOF Catalytic Ozone Oxidation Stably Treats Heavy-Fuel-Oil Wastewater
In the environmental-governance landscape of the power industry, the cleaning wastewater from heavy-fuel-oil storage-tank farms is a typical challenge. This wastewater contains large amounts of pollution factors such as oil, COD and BOD, with complex composition and fluctuating concentration. Traditional simple oil separation can only intercept part of the floating oil, and the effluent can hardly meet the tertiary discharge standard of the Integrated Wastewater Discharge Standard (GB 8978-1996); environmental pollution and compliance risks persist over the long term.
SINOKLE's three-stage synergistic deep-treatment process of "CDFU cyclonic dissolved air flotation + JuJie coalescing oil remover + CDOF catalytic ozone oxidation" provides a systematic solution. Why can this process stably meet standards? This article breaks it down from technical mechanism to engineering value.
1. Dissect the difficulty: the three pollution factors of tank-farm cleaning wastewater
Oil. The oil forms in the wastewater are complex: floating oil has good floatability and is relatively easy to intercept; emulsified oil is stably dispersed in water as tiny droplets covered by an interfacial film, which ordinary oil separation cannot break; dispersed oil lies in between. If the oil is not thoroughly removed, neither the sensory nor the indicator requirements of the effluent can pass.
COD. Tank-farm cleaning wastewater is rich in hydrocarbons and other organics, with high COD. COD reflects the oxygen consumed by chemical oxidation and is the core indicator of organic-pollution load; it must be effectively degraded to comply.
BOD. Reflects the content of biodegradable organics. High-BOD wastewater discharged into water bodies rapidly consumes dissolved oxygen and damages the aquatic ecosystem. BOD and COD together form the dual pressure of organic pollution.
The limitation of simple oil separation is that it "can only intercept floating oil": it cannot break emulsified oil or reduce COD/BOD — none of the three pollution factors is truly solved.
2. Dissect the solution: the gradient-governance logic of three-stage synergy
Stage 1: CDFU — physical separation, demulsify and remove oil. CDFU (Cyclonic Dissolved Gas Flotation Unit) is a proprietary patented technology independently developed by SINOKLE with internationally advanced levels. It organically combines cyclonic centrifugal separation, micro-fine bubble generation and dissolved air flotation, representing a new generation of efficient, compact, enclosed and pressurized flotation technology pioneered domestically. Its working principle operates on two levels: first, microbubbles bring the foul oil to the water surface; second, the microbubbles play a demulsifying role, destroying the interfacial film of emulsified oil and releasing the "hidden" oil. The cyclonic centrifugal force further strengthens oil-water separation, achieving efficient and rapid separation of foul oil, emulsified oil and suspended solids. This stage solves the separation problem of "how oil comes out of the water".
Stage 2: JuJie coalescing oil remover — fiber interception, oil recovery. After CDFU coarse separation, the wastewater enters the JuJie coalescing oil remover. It achieves fine oil-water separation through special coalescing fibers, intercepting residual oil droplets. The key value of this stage is twofold: first, it makes the effluent cleaner and reduces the downstream oxidation load; second, it collects the separated foul oil for reuse, realizing resource utilization — solving both the problem of "how to remove residual oil" and "how to recover the oil".
Stage 3: CDOF — oxidative degradation, guaranteeing compliance. CDOF (Cyclonic Dissolved Ozone Flotation Unit) is an ozone advanced catalytic oxidation-flotation integrated unit that integrates ozone multi-catalytic oxidation, hydrodynamic cavitation and cyclonic dissolved air flotation. It is domestically original, internationally leading, and protected by PCT international patents. The unit consists of an oxygen-generation system, ozone-generation system, efficient ozone-dosing system, multi-catalytic reaction system and cyclonic dissolved-air flotation system, realizing synergy among homogeneous/heterogeneous catalysis, cyclonic flow, dissolved-air flotation, cavitation and supercritical catalytic oxidation in a fully enclosed pressurized oxidation environment. Highly active oxidants decompose the refractory pollutants in the wastewater and reduce COD — solving the final problem of "how to degrade dissolved organics" and guaranteeing stable effluent compliance.
3. One comparison table: simple oil separation vs three-stage synergistic deep treatment
| Comparison item | Traditional simple oil separation | CDFU + JuJie remover + CDOF three-stage |
|---|---|---|
| Treatment capacity | Only intercepts part of floating oil | Three-stage synergistic deep treatment, stable compliance |
| Oil removal | Limited floating-oil interception, emulsified oil hard to break | CDFU microbubble demulsification + cyclonic separation, efficient removal of foul & emulsified oil |
| COD/BOD removal | Essentially cannot be reduced | CDOF catalytic ozone oxidation decomposes refractory pollutants, reduces COD |
| Oil recovery | No or difficult recovery | JuJie remover collects oil for reuse |
| Discharge standard | Hard to meet GB 8978-1996 tertiary | Effluent stably meets GB 8978-1996 tertiary |
| Technical advancement | Conventional open separator | CDFU domestically first, CDOF domestically original, PCT patent |
| Equipment form | Large tanks, large footprint | Efficient compact enclosed pressurized units |
4. Why is it "1+1+1 > 3"?
The three-stage synergy is not a simple stacking of three sets of equipment, but a complete governance chain built on the gradient logic of "physical separation → fiber recovery → chemical degradation":
Clear division of labor. CDFU handles "how oil comes out", the JuJie remover handles "how oil is removed + recovered", and CDOF handles "how COD is degraded" — each stage does only what it is best at, maximizing treatment efficiency.
Progressive load reduction. CDFU first removes the bulk of the oil and reduces the downstream load; the JuJie remover then finely intercepts and lowers the organic concentration; CDOF focuses on degrading refractory substances — the higher the upstream treatment quality, the more efficient the downstream oxidation and the more stable the overall process.
Engineering deployment. CDFU's efficient compact enclosed pressurized design and CDOF's integrated design give a small footprint, high system integration and short installation/commissioning cycle, with good engineering deployability especially suited to power-station site conditions.
5. Summary
The treatment difficulty of tank-farm cleaning wastewater roots in the superposition of "complex oil forms + high organic load"; the limitation of simple oil separation roots in "only intercepting floating oil, unable to break emulsified oil, unable to reduce COD". The three-stage deep-treatment process breaks through gradient by gradient with the logic of "separation-recovery-degradation": CDFU demulsifies and removes oil, the JuJie remover finely recovers, and CDOF catalytically degrades, so that the final effluent stably meets the GB 8978-1996 tertiary standard. For heavy-fuel-oil power stations, this is a deep-treatment solution that withstands scrutiny from mechanism to engineering.
