Four Projects, One Filter Media: Field Evidence Behind SFM Super-Hydrophilic Filtration

Marketing sheets are easy to write; five-year effluent logs are not. For an industrial filter media, the honest test is what happens in the field — and the SFM super-hydrophilic modified self-cleaning media from SINOKLE now has four documented cases across domestic oilfields, an overseas oilfield and an overseas power plant, spanning 2017 to 2025.

The Science Underneath

SFM is developed from interfacial molecular dynamics and microfluidics theory, with dual modification: covalently grafted chemical functional groups plus physical micro-nano rough structures. The result is a surface with extreme wettability in both directions — super-hydrophilic and underwater super-oleophobic — with a water contact angle below 5 degrees and an underwater oil contact angle above 150 degrees. A 20–80 nm nano-hydration isolation layer stops oil droplets adhering or spreading, while high-frequency collisions inside the micro-channels of the pores weaken the emulsified film until droplets coalesce spontaneously. Oil droplets grow past 50 micrometres and detach at critical shear, holding a dynamic capture–coalescence–detachment equilibrium. Separation precision reaches down to 0.45 micrometres, fine oil droplet removal is no less than 90%, and effluent oil sits consistently below 5 mg/L.

Four Projects, Four Conditions

Changqing Oilfield, 2017

A produced-water treatment project delivered in 2017 with 20 m³/h of capacity, built as a two-stage CDFU plus SFM filter combined process. Influent oil runs up to 1,500 ppm; the SFM effluent stays below 5 ppm, suspended-solids removal exceeds 95%, and the system has held stable over the long term.

PetroChina Huabei Oilfield, 2020

Delivered in 2020 at 10 m³/h, using two-stage CDFU cyclonic dissolved-air flotation plus SFM filters. No chemicals are dosed anywhere in the process; effluent oil and suspended solids both stay below 5 mg/L, meeting the effluent standard.

Republic of the Congo, 2023–2025

The benchmark overseas project for SINOKLE: Phase I, at 4,600 m³/d, was commissioned in 2023, and Phase II expansion brought the scale to 6,500 m³/d in 2025. The CDFU + CDOF + SFM combined process handles complex streams — oilfield produced water and fracturing flowback fluid — with stable, compliant effluent quality.

Sierra Leone heavy-oil power plant, 2025

Delivered in 2025 at 10 m³/h, again two-stage CDFU cyclonic dissolved-air flotation plus SFM filters. Purely physical oil removal with no chemical dosing; effluent oil and suspended solids below 5 mg/L, achieving efficient purification of oily wastewater.

The Operating Economics

Reading the Case Data Correctly

Three details in those project logs deserve attention. First, the influent qualities differ sharply — an oilfield with 1,500 ppm of oil, a shale-style produced water stream, and a power plant burning heavy oil are three different separation problems, yet the same media held spec in all of them. Second, the absence of chemical dosing at Huabei and Sierra Leone is not incidental: it removes flocculant cost, sludge handling and dose-control labour in one move. Third, overseas delivery is itself a durability test — remote sites punish any media that needs frequent backwash supervision or early replacement, and both the Congo train and the Sierra Leone unit were specified accordingly.

The four projects rest on plain economics: continuous operation cycles of 24–48 hours with constant pressure drop and no dead zones; system conveyance energy consumption down 30–50%; backwash water consumption down more than 60%; operation cycles extended 3–5 times. Backwashing with ordinary-strength clean water restores the initial clean state with nearly 100% lossless performance recovery. The covalently bonded layer resists acids and alkalis across pH 2–12 plus abrasion, with a design service life beyond 5 years. The process is green in the literal sense — physical oil removal and coalescing demulsification generate no oily sludge, and the recovered oil can be recycled.

Against the Traditional Benchmarks

Walnut-shell and ordinary quartz sand media work by mechanical sieving plus adsorption or surface attachment, from a weakly hydrophilic or even hydrophobic-lipophilic interfacial state. The gap shows in every number: their separation precision sits around 5–10 micrometres, continuous cycles only 4–12 hours, post-backwash recovery 70–80%, service life 1–3 years. SFM instead combines hydration-layer interception, interfacial coalescence and physical cell-wall-disruption bacteriostasis — precision down to 0.45 micrometres, effluent oil below 5 ppm, 24–48 hour cycles, 99.5% post-backwash recovery and a life beyond 5 years, which is what a lower full-cycle operation and maintenance cost actually looks like.

What to Verify in Your Own Trial

A short field trial settles most doubts. Measure the influent droplet distribution first, because the media advantage is largest where droplets are fine and emulsified. Then track three numbers across the trial: effluent oil stability across a full backwash cycle, pressure-drop behaviour over the claimed 24–48 hour window, and post-backwash recovery against the baseline. Projects that verify those three tend to find the published economics transfer directly to their own site.

Fit and Flexibility

For both new-built and upgrading projects, SFM can be embedded directly as a deep-filtration unit into an existing flow, or combined with CDFU and CDOF equipment into a complete oil-removal chain. From oilfield produced water to power plant oily wastewater, from domestic to overseas sites, the case record argues that long life and low consumption are verifiable engineering outcomes — stable compliance, low-consumption operation and recyclable recovered oil, exactly what the green, low-carbon transition of industrial wastewater treatment calls for.