KHC-F2001 and CDOF: Pairing a Silica-Alumina Ozone Catalyst with an Integrated Flotation Unit

Advanced ozone oxidation earns its place in water treatment for two reasons: it oxidises strongly enough to break molecules that biology cannot, and it leaves no reagent residue behind. Against that, conventional implementations carry three persistent complaints — low ozone utilisation, high operating cost per cubic metre, and an equipment footprint that is hard to fit into an existing plant.

The gap between ozone chemistry and ozone performance is where most of the engineering effort goes. Ozone that dissolves but does not react is simply an expensive way to aerate a tank. SINOKLE addressed the gap from two directions at once: a catalyst that converts dissolved ozone into something more aggressive, and a vessel that keeps catalyst, ozone and wastewater in contact long enough for the conversion to pay off.

The Catalyst: KHC-F2001

The KHC-F2001 is a silica-alumina-based ozone catalyst that blends multiple transition metal oxides, precious metals among them, as active components. Manufacturing is where the performance is set: multi-stage precisely temperature-controlled sintering combined with a unique pore-forming process produces what the company describes as a triple advantage — high strength, high specific surface area and high catalytic activity.

Each of those three matters for a different reason. High strength means the media survives backwashing and thermal cycling without breaking down into fines that blind the bed. High specific surface area means more active sites per cubic metre of reactor, which is what allows a smaller vessel to do the same duty. High activity means the sites turn ozone over quickly rather than holding it. The catalyst is also resistant to acid and alkali corrosion and easy to recycle, which matters because a catalyst that has to be replaced as hazardous waste is a cost that never appears in the performance table.

In reaction, the catalyst promotes the decomposition of ozone into hydroxyl radicals, raising ozone oxidation efficiency by 2-5 times. That multiplier is the answer to the utilisation complaint: the same ozone generator, the same power draw, several times the oxidative work done. It also solves, at the root, the problem of insufficient ozone utilisation in conventional processes, which is what makes downstream treatment efficiency possible in the first place — an oxidation stage that leaves refractory organics behind simply moves the problem to whoever owns the next unit.

The Vessel: CDOF

CDOF is a domestically patented technology and, in effect, the packaging that makes the catalyst usable at plant scale. It merges three core technologies — advanced ozone oxidation, swirl separation and dissolved air flotation — into a closed-loop treatment sequence of oxidation, demulsification and separation.

The micro and nano oxygen bubbles inside the unit do more than one job. They clean the catalyst surface, which prevents caking and blockage; they strengthen the contact reaction between ozone and the catalyst; and they remove suspended solids, colloids and oils from the wastewater, reducing the non-dissolvable COD load and further cutting ozone consumption. That last effect is easy to miss and important: every milligram of oil that flotation takes out is a milligram of ozone that does not have to be spent on it.

The comparison against conventional processes is stated in four numbers. Reaction time falls from 60-90 minutes to 5-10 minutes. Footprint falls by 80%. The ozone dosing ratio drops from 2-4 to 0.5-1.2. Operating cost comes down to 1/3-1/2 of conventional technology. Taken together, they shift the technology from something reserved for polishing duty into something that can carry a main treatment role.

Landfill Leachate: Hubei and Zhejiang

In a landfill leachate treatment project in Hubei, the unit reduced influent COD from high concentration to compliant levels — the kind of statement that only means something when the starting number is stated, which is why the Zhejiang project is the more useful reference.

At the Zhejiang landfill project, COD removal exceeded 80%, with effluent COD reduced from 1500 mg/L to below 200 mg/L. More significant than the removal rate is what happened to biodegradability: the B/C ratio rose from 0.22 to 0.37. That rise creates the conditions for subsequent biochemical treatment, which changes the economics of the whole plant — the oxidation stage is no longer a substitute for biology but a preparation for it, and biology is cheaper per kilogram of COD removed.

Petrochemical Wastewater: Xinjiang

The Xinjiang petrochemical wastewater project tested a different duty. With an ozone dosage of 100 ppm, COD removal exceeded 90% and oil content dropped from 35 ppm to 2.3 ppm. Oily sludge generation fell by more than 90%, and the site saves over one million yuan a year in hazardous waste disposal costs alone.

That last figure deserves attention because it is not an energy saving or a chemical saving; it is the avoided cost of classifying, storing, transporting and incinerating hazardous waste. In jurisdictions where the manifest chain is expensive, sludge reduction is often the largest single line in the business case, and it is the one most often omitted from a vendor comparison.

Where the Combination Fits

The pairing of CDOF with KHC-F2001 has been validated on landfill leachate and petrochemical wastewater, which are two of the harder duties in the field — one dominated by refractory humic material and salts, the other by emulsified oil and sulphides. The same configuration is offered for pharmaceutical, metallurgical and other industrial streams.

The design characteristics that make it usable in those settings are as much mechanical as chemical: fully automated enclosed operation with near-zero ozone leakage, and strong resistance to shock loading. An ozone plant that leaks is a safety problem; an ozone plant that cannot tolerate a slug of high-COD water is an availability problem. The combination claims to have addressed both, and the enclosed design is what allows the unit to sit close to the process it serves rather than at the boundary fence.

What remains for a buyer to check is site-specific: the right catalyst volume for the actual COD load, the ozone dose the permit will tolerate, and whether the downstream biology exists to take advantage of the improved B/C ratio. Those three questions decide whether the technology delivers its paper performance or its real one.