A New Solution for Oily Wastewater Treatment at Heavy-Oil Depots: An In-Depth Analysis of SINOKLE's Two-Stage CDFU Combined Process
A New Solution for Oily Wastewater Treatment at Heavy-Oil Depots
In the environmental protection work of oil depots, oily wastewater treatment is an unavoidable topic; when the subject becomes a heavy-oil depot, the difficulty rises another notch. The oily wastewater from tank draining is highly emulsified and oil-rich, with oil and water tightly intertwined, making it especially intractable. Many depots have installed multiple facilities, yet the effluent still struggles to stably meet the discharge requirement of oil content ≤10 mg/L — facilities, chemicals and costs keep rising, yet compliance remains uncertain.
Scenario: What Makes Heavy-Oil Draining So Difficult?
First, let us look at the particularity of this application scenario. The oily wastewater at heavy-oil depots mainly comes from tank draining. The oil itself has high viscosity and complex composition; during draining and transfer it is repeatedly agitated, and the oil is dispersed into fine emulsified droplets wrapped in a stable interfacial film. This "oil-in-water" emulsion is extremely stable, and conventional quiescent gravity separation or ordinary flotation simply cannot break it open effectively. Coupled with the high incoming oil content and load, the effluent indicators fluctuate with the incoming water, making stable compliance hard to achieve.
The Key Breakthrough: CDFU — Patented Fusion of Multiple Separation Mechanisms
Facing the emulsification challenge of heavy-oil draining, SINOKLE chose to focus its breakthrough on the independent R&D of core equipment. CDFU is SINOKLE's independently developed patented technology — a new-generation, domestically pioneered, high-efficiency, compact, enclosed, pressurized flotation unit. Its excellence lies in not stopping at the single mechanism of traditional flotation, but organically fusing multiple technologies such as cyclonic centrifugal separation, ultrafine bubble generation, dissolved air flotation, coalescence and demulsification.
Cyclonic centrifugal separation forms a swirl field within the enclosed chamber, using centrifugal force to preliminarily stratify oil, water and solids; ultrafine bubble generation combined with dissolved air flotation releases a large number of fine micro-bubbles, providing ample "transport carriers" for oil droplet rising; coalescence and demulsification strike directly at the crux of emulsified oil — coalescence lets fine oil droplets merge and grow, while demulsification destroys the stability of the oil-water interfacial film, completely stripping the protection from the previously "huddling" emulsified oil. The multi-mechanism synergy achieves efficient and rapid separation of waste oil, emulsified oil and suspended solids from the wastewater.
Process Design: Two-Stage CDFU as the Core Combined Process
Targeting the highly emulsified, oil-rich water quality of heavy-oil draining, SINOKLE builds a combined process centered on two-stage CDFU cyclonic dissolved air flotation, forming a complete treatment chain:
Primary coarse oil removal → Secondary deep oil removal → Activated-media filter → Compliant effluent
Primary coarse oil removal: The first CDFU unit undertakes the main separation task, rapidly removing large amounts of free waste oil and suspended solids, significantly reducing the overall system load.
Secondary deep oil removal: The second CDFU unit takes over for further treatment, performing refined separation on emulsified oil and fine oil droplets to further compress the oil content, leaving ample margin for end-of-line compliance.
Activated-media filter: The end-of-line guardian unit, intercepting and filtering fine residual pollutants in the upstream effluent, adding another layer of insurance for stable compliance.
Worth mentioning is the closed-loop design of the entire flow: the waste oil separated by the two CDFU stages is not waste, but is uniformly collected into a waste-oil collection tank for recovery and reuse. Pollution control and resource recovery are accomplished within the same system, achieving both environmental protection and economic benefit.
From Scenario to Answer: What Changes Does This Process Bring?
The value of this process can be summarized in four points:
Stable compliant effluent. The two-stage series plus end-of-line filtration structure provides ample design margin for the water-quality fluctuations of highly emulsified, oil-rich incoming water, and the effluent stably meets the discharge requirement of oil content ≤10 mg/L.
Fully physical throughout, no chemicals required. It breaks free from dependence on demulsifiers and flocculants at the source, eliminating both chemical costs and dosing operations.
No oily-sludge hazardous waste. The physical separation route naturally avoids the oily-sludge problem associated with chemical methods, greatly reducing hazardous-waste disposal pressure.
Waste-oil recovery and reuse. The separated waste oil enters the collection tank for recovery and reuse, achieving unity of environmental protection and economy.
The treatment of oily wastewater at heavy-oil depots has always tested not merely the single-point capability of equipment, but the overall competence of "water-quality assessment — technology selection — process design". With its independently developed CDFU patented technology as the core and the two-stage combined process as the framework, SINOKLE provides a complete solution — from scenario pain points to a stable-compliance closed loop — for the treatment of highly emulsified, oil-rich heavy-oil draining. For depot owners and engineering contractors looking for a breakthrough, this solution is worth studying and verifying in the field.
