Oily ship bilge water at ports: meeting Tier-3 discharge in a footprint cut by 60%
Two constraints collide at any port handling oily ship bilge water: there is nowhere to put a treatment plant, and there is no tolerance for a non-compliant discharge. With the revised Marine Environment Protection Law in force, supervision of oily water discharges from ships is tightening, and wastewater treatment at ports and marine cloud warehouses has become a compliance imperative rather than a service amenity.
The water itself resists easy handling. Oily ship bilge water is complex in composition, and conventional solutions often fail to meet standards reliably when space is tight and the water quality shifts from vessel to vessel. SINOKLE has purpose-built a dedicated port / marine cloud warehouse solution around this stream, using zero chemicals and an intelligent skid-mounted design so that effluent reliably meets the comprehensive Tier-3 discharge standard.
Why the process chain is short by design
The solution combines CDOF (catalytic ozonation) and CDFU (cyclonic dissolved gas flotation) into a dedicated treatment chain for oily ship bilge water. The chain meets the oily wastewater compliant discharge requirements of the Marine Environment Protection Law and the comprehensive Tier-3 standard while addressing four needs at once: compliance, space saving, ease of operation and cost control.
Keeping the chain short is a deliberate choice for this application. Every additional vessel adds pumps, instruments, operator training and floor area, and a port berth has no room for any of it. Two process stages that each remove a well-defined fraction of the load are easier to run than four that overlap.
Three advantages that address the actual pain points
Zero-chemical physical treatment. No reagent is dosed when treating oily ship bilge water, so there is no chemical residue, no secondary pollution and no reagent logistics on a quay. Compliance rests on separation rather than on dosing accuracy, which is a more reliable basis when the feed changes daily.
Intelligent skid-mounted design. Footprint is reduced by 60%, fitting the limited space of port berths and marine cloud warehouses, with installation and commissioning completed in 10 days. A ten-day window is short enough to plan around a berth closure.
Compliance and cost reduction combined. After treatment, oil content in oily ship bilge water is 10mg/L or less and COD is 500 mg/L or less, reliably meeting the Tier-3 discharge standard, while energy consumption drops by 40%. Drawing on 30 plus patented technologies, SINOKLE continuously iterates its processes and optimises corrosion resistance and shock resistance, which matters for equipment that sits in a salt-laden atmosphere.
Two installation patterns, two different problems solved
In the domestic market SINOKLE has established deep cooperation with PetroChina and CNOOC, providing polymer-bearing wastewater solutions for their oilfield blocks. For oilfield wastewater characterised by high oil content, complex composition and large water-quality fluctuations, the configuration is CDFU cyclonic dissolved gas flotation plus CDOF pretreatment and catalytic ozonation advanced treatment. The combination achieves high-standard effluent and reduces manual intervention through intelligent O&M systems, cutting O&M costs by 30%.
Marine cloud warehouse projects present a different shape of problem: limited space and concentrated wastewater arriving in batches. Compact intelligent units treat oily ship bilge water efficiently, meet the Tier-3 discharge standard and integrate collection, treatment and discharge into one operation. The two patterns are not variants of the same drawing; they respond to whether the constraint is continuous flow at a berth or batch arrival at a warehouse.
Deciding on a configuration
On the technical side the question is whether the bilge water carries enough emulsified oil to need flotation ahead of oxidation, or whether catalytic ozonation alone can carry the COD load. On the decision side the question is whether on-site treatment beats transfer to a licensed facility. On-site treatment cuts transfer costs, and with energy consumption falling by 40% the long-term return is significant.
SINOKLE focuses on oily ship bilge water and port and marine cloud warehouse treatment, refining intelligent, efficient solutions that support the industry's green and compliant development. For operators facing a berth with no spare square metre, the practical test is simple: can the unit be installed inside the available footprint and still produce 10mg/L or less oil and 500 mg/L or less COD on the worst feed of the year. That is the standard this solution is designed against.
Two practical notes for a procurement discussion. First, the footprint figure of 60% reduction is measured against a conventional chain of equal capacity, so the comparison should be made on a like-for-like flow basis. Second, the 10-day installation figure assumes the skid arrives complete and the quay has a working power supply; civil works for a collection pit and discharge point sit outside that allowance. Getting those two assumptions stated in the contract avoids the usual dispute about who owns the delay.
One more point on operating cost, because it is the number that survives the project. Energy consumption falling by 40% matters most where the plant runs continuously rather than seasonally, which is the case for a berth serving regular traffic but not necessarily for a warehouse handling occasional barge transfers. The savings case should therefore be built on the actual operating hours of the site rather than on a full-year assumption. Where utilisation is genuinely continuous, the payback calculation is straightforward; where it is intermittent, the footprint and compliance benefits usually carry the decision instead.