Galley FOG recovery and prevention

Greywater treatment is more than just an obligation

The importance of greywater treatment cannot be overstated from an environmental sustainability perspective. Greywater is generated in maritime activities as a byproduct of washing and cooking. Greywater also entails ecological and regulatory implications. The use of efficient greywater treatment solutions not only ensures compliance with regulations but also promotes a greener and more sustainable maritime industry.

Greywater treatment refers to the removal of impurities, particles, and pollutants before releasing water into the sea. This reduces the impact of wastewater on the marine ecosystem. Uncontrolled discharge of greywater into the sea can disrupt marine life balance due to increased nutrients, decreased oxygen, and spread of harmful pathogens.

By investing in advanced greywater treatment technologies, ships can significantly reduce their environmental impact. Modern water treatment systems utilize state-of-the-art filtration, chemical, and purification processes to ensure that greywater meets international emission standards. This protects marine biodiversity and maintains the ship's reputation as a responsible operator.

Proper greywater treatment improves ship hygiene and comfort. Removing impurities from wastewater reduces odors and potential health risks.

Modern greywater treatment on ships goes beyond compliance with regulations. It directly promotes ecosystem preservation, supports sustainability, and raises the ship's quality standards. Effective greywater treatment is not just a legal obligation but a step towards a more sustainable future of maritime transport.

What is Fats, Oils, and Grease (FOG)?

FOG is an international abbreviation for fats, oils, and grease. FOG waste accumulates in the ship's greywater pipelines. FOG waste is generated in cooking from fats, food residues, cooking oil, butter and margarine, sauces, mayonnaise, salad dressings, sour cream, and other fatty ingredients. When FOG waste enters the pipes, it can solidify, causing blockages and overflows. FOG waste also reduces the system's capacity (slows down flow) and disrupts the wastewater treatment process. As a result, the ship's crew must spend significant time and effort removing accumulated fats and oils.

Installing grease and oil separators in galleys is a legal requirement. Failure to install separators can cause problems in the ship's collection tanks, where greywater ends up. When fat and oil accumulate on the surface of the tank, they inhibit nitrogen metabolism, promoting the growth of anaerobic bacteria. This results in the production of corrosive sulfuric acid, which is further promoted by the effect of chemicals used in the system. Sulfuric acid damages steel bulkheads and combines with chlorine used in water purification, producing dangerous gases in confined spaces.

SmartPipe's Solution for Greywater Treatment

Step 1 – Fat Separation

Our two-step solution for greywater treatment and pipeline maintenance is simple. In the first step, waste accumulated from fats and oils is collected using Filta FOG Cyclone devices, which effectively separate food waste and FOG from the solution before it enters the sewer network.

Traditional grease separators are usually inefficient, but the advanced (and compact) Filta FOG Cyclone cleans water to an FOG level as low as 16 ppm. In other words, after passing through the Cyclone separator, there are only up to 16 milligrams of fat and oil residues in a thousand liters of greywater.

Made of stainless steel and without moving parts, the Filta FOG Cyclone is the leading grease recovery unit / grease separator on the market. The device collects FOG waste and uses significantly less energy for collection than traditional grease separators (GRUs). The airtight units are designed to be environmentally friendly. The Cyclone's grease collection cartridge is easy to clean, making the device extremely user-friendly.

Step 2 - Pipeline Bacterial Treatment

In the second step, we use high-quality, multi-strain BioTroop BL-20 microbial solution dosed into the sewer. This efficient and eco-friendly solution reduces FOG problems in the sewer network and grease separators.

The bacteria in the solution break down triglycerides and fatty acids. However, they are not limited to fats and oils derived from food. The bacteria in BL-20 also break down other organic wastes in traditional pipelines, suction lines, drains, and grease separators.

In the decomposition process generated by the solution, bacteria also form a "community" of billions of bacteria, biofilm, on the inner surface of the pipe, making it difficult for fats to adhere and preventing pipe blockages. Therefore, the biological treatment process is important to start even in new and clean pipes.

BioTroop BL-20 is dosed daily with an automatic Inntech DPT pump. The pump is programmed to feed, for example 150–200 ml of solution per day, usually at night or when the kitchen is not in use.

Alternatively, BioTroop BL-20 can also be poured manually into the sewer by mixing the solution with water.

Filta FOG Cyclone - Grease Separator

  • The world's first hydrocyclone-enhanced grease recovery unit, with 8 independent hydrocyclones
  • Unique two-stage FOG separation and recovery
  • Extremely low amount of FOG waste at the outlet, only 16 ppm
  • Compact outlet, no gas or sewer odor
  • Self-closing inlet tube prevents food waste from passing through
  • No need for grease hardening removal, reducing cleaning time, improving hygiene, and reducing odor
  • Low-level vortex works together with low-standing combination ovens
  • Low energy consumption compared to other grease separation units, saving thousands of euros over the unit's life cycle
  • Made of stainless steel, 10 year warranty
  • Easy-to-use FOG container is quick to clean
  • No heating element
  • High-quality collected oil can be added to used cooking oil for biofuel use
  • FootPrint Award 2022
  • Patent pending

Contact our professionals:


Mikko Eskola

Director R&D, Business Development
+358 50 5550660

Subscribe to our newsletter

We send mail occasionally and you may unsubscribe from the newsletter at any time.