Smell removal from blackwater and graywater tanks with Ozone

Smell removal from blackwater and graywater tanks with Ozone

Smell removal from blackwater and graywater tanks with Ozone

Ships and pleasure yachts have always had to face a problem whose solution is far from simple: the smells coming from the black and gray water tanks. Tanks of black and gray water on board yachts are inevitably a source of unhealthy gases and bad smells. These gaseous mixtures are then conveyed upwards through vent pipes and expelled into the atmosphere. However, it often happens that bad odor gases are released in lived-in areas of the yacht (such as the Sundeck), generating discomfort and discontent on board.

What are the conventional solutions for the treatment of smells due to black and gray water?

The most used solution to stem the problem of bad smells due to black and gray water tanks is undoubtedly mechanical filtration using activated carbon. However, activated carbon filters are increasingly considered an outdated and in many ways inconvenient choice.

For example, nowadays most pleasure boats and mega yachts use vacuum pumps for their sanitary facilities: this system, which is very comfortable and efficient, generates an important and rapid flow of air along the vent pipes. This flow of gas from the black water or gray water tank would need to flow as freely as possible along the air vent of the yacht but this is not possible due to the activated carbon filter which represents an obstacle for the outgoing air. In these cases, the activated carbon filter creates a backpressure that can give rise to problems such as the return of odors from the drains or, even worse, real micro-cracks along the vent line from which bad smells can come out and spread on board in the most unexpected areas.

Finally, it should be remembered that the performance of the activated carbon filter decreases rapidly and this element therefore needs to be replaced at least every 6-12 months (an operation that is often complex due to the location of the filter).

What is the solution offered by Protea for the treatment of smells due to black and gray water?

The solution offered by Protea is a special ozone generator specifically designed to eliminate odors from the black and gray water tanks: PROWAT. Ozone is a hyperoxidant capable of drastically reducing bacteria, viruses, odors, molds, algae, fungal spores and other sources of unhealthiness: therefore, Ozone has the prerogative of effectively eliminating bad smells through an oxidation process and not of simply covering or disguising them (like the countless products on the market).

The Ozone produced by Protea ozonizers branded PROWAT system is injected at various points along the vent pipe of the black or gray water tank, quickly and effectively eliminating the odorous substances it encounters. The air expelled from the air vents is therefore odorless.

What are the advantages of using Protea ozonizing systems instead of the conventional solutions?

The advantages of using Protea ozonizers as opposed to commonly used activated carbon filters are many.

  • No recharges. Ozone is produced from the Oxygen present in the air. Basically, PROWAT only needs electricity with which it produces Ozone autonomously by feeding itself with the ambient air.
  • Free installation. The systems can be positioned about ten meters away from the Ozone injection point, so as to allow their placement according to the spaces available on board. Not only new boats, therefore, but also already sailing yachts, yacht charter and motor yachts in refit. A single PROWAT system can also treat multiple tanks or vent pipes, with consequent economic savings and technical simplifications for the Shipyard or for the Customer.
  • No back pressure. PROWAT injects Ozone into the established points by means of special injectors supplied by Protea ozonizers. In this way, no backpressure is created on the vent line but the gases can escape freely, avoiding the return of odors to the drains onboard and on the yacht in general.
  • No particular maintenance. Protea ozonizers constantly strives to create systems capable of operating as autonomously as possible and with minimal maintenance. The new PROWAT systems, thanks to the latest upgrades, do not need maintenance but only some simple periodic checks as a good rule for every electrical aid. The economic savings are therefore considerable considering the high cost of maintenance and replacement operations of the filter.
  • Cancellation of warranty costs. PROWAT ozonizing systems for pleasure yachts represent a great advantage for the Shipyard by eliminating problems to which the Shipyard should respond.

PROWAT ozonizer: a fundamental system to have on board

The problem of bad smells coming out of the air vents of black and gray water tanks is a general and common problem on pleasure yachts, whether it is a motor yacht under 24 meters, a mega yacht or a giga yacht, and not must be underestimated. PROWAT represents the definitive solution to this problem and, for this reason, it is not to be considered one of the many accessories of yachts supply but a fundamental system to have on board as well as an essential element of the entire gray water and blackwater treatment plant and related odors.

For more information on Protea ozonizers or Protea’s Ozone solutions for the Marine Industry or other applications, do not hesitate to contact our offices at 0584/361274 or by email at


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