Alfa Laval - Choosing a system

Choosing a ballast water treatment system

See our 11-point selection guide that will help you choose the system that’s best for you.

1. Is your chosen system type approved by both IMO and the U.S. Coast Guard?

Compliance with the recently ratified IMO Ballast Water Management (BWM) Convention is a must. It's also vital to check for a recent IMO type approval certificate.

Systems evaluation has evolved since the BWM Convention was adopted in 2004. Certificates issued by authorized third-party bodies now provide more details about testing as well as information concerning the system's operating limitations, salinity, temperature and UV transmittance levels.

Be aware of national and regional regulations. In order to deballast in United States waters, a vessel's ballast water treatment system must be type approved by the USCG.

Vessel compliance with USCG legislation increases resale value. Without it, buyers wishing to operate in this key market are unlikely to invest.

With all type approvals, look for certificates issued by an authorized third party to ensure greater validity and increased transparency.

2. Has water with naturally occurring organisms been used in certification?

Type approval certificates issued by an authorized third party ensure a controlled testing environment and realistic test conditions.

For example, organisms that live close to the water's surface are more resistant to UV light and are best treated with medium-pressure UV lamps.

By using a uniform mixture of selected and cultivated organisms during testing, results may show them being removed. This does not match with real world situations, where water is not regulated and organisms are hardier and more varied.

Serious suppliers understand the real-world implications of non-compliance. They choose robust UV technology, seek third-party transparency and pro-actively stress their systems to ensure resilience.

Natural water with non-cultivated organisms such as polychaetes, rotifers and shrimp should be used, ideally in the presence of difficulties such as algae blooms.

3. Is your system specifically designed for marine use?

Surprisingly, most ballast water treatment systems have their roots in on-land drinking water treatment. Rather than being developed for purpose, their technology has been adapted to try and meet the needs of the marine environment.

Land-based UV treatment systems deal with less complex water environments and other cleaning processes run before treatment begins.

Ballast water treatment systems face difficult organisms, irregular water quality, higher temperatures and long periods of standstill with saline water inside them. Only a system specifically designed for marine conditions is properly equipped for these challenges.

4. Will your system's key components resist corrosion in seawater?

Many ballast water treatment systems make key components from lower-grade materials, such as 316L steel. While 316L is a common engineering material, it corrodes in contact with seawater.

A 316L steel UV treatment reactor, which is filled with seawater throughout the treatment process, may corrode and need replacement in as little as five years.

254 SMO and AL6-XN Super austenitic stainless-steel resist seawater corrosion. Key components made of these materials last much longer. UV reactors made of AL6-XN can last up to 20 years or more.

5. Does your chosen system make maximum use of the UV light produced?

To make UV treatment biologically effective and energy efficient, the UV light the lamps produce must reach the targeted organisms.

The reactor's internal construction should distribute high levels of UV light evenly and create high turbulence in the water passing through it to ensure that a concentrated dose reaches all organisms.

Low-clarity waters, where UV transmittance is lower, require stronger measures. Specially designed lamp sleeves of synthetic quartz support transmission of a broader wavelength spectrum and provide more UV light for disinfection. Any reliable system needs this capability.

6. Does your system offer effective power management?

Both biological disinfection performance and energy efficiency are key to power management. To ensure compliance, ballast water treatment systems use the least possible amount of power.

To handle difficult scenarios such as low UV transmittance without compromising vessel operations, they also need power in reserve. Compromised operations risk reducing ballast water flow rate or even preventing entry into these waters.

7. Does your system have an automatic Cleaning-In-Place (CIP) cycle?

Without regular cleaning, calcium carbonate deposits and metal ions build up on the quartz sleeves of the UV lamps. This blocks some of the UV light and impairs treatment.

Mechanical wiping is ineffective against the build-up of metal ions, which must be removed with a low-pH fluid and an additional process. Wiping does not clean the UV sensor that measures UV transmittance and regulates power usage, which can lead to excessive power usage and low performance.

Mechanical and manual cleaning of any kind leads to sleeve scratches, which degrade treatment performance.

Tests show that CIP helps maintain the biological disinfection performance of ballast water treatment systems. In a UV-based system, the effects are noticeable after a single cleaning operation.

8. Are comprehensive monitoring and hardwired safety functions present?

Safety is paramount on board. UV-based systems are safer than those reliant on chemicals, but any system must put safety first to prevent serious damage to equipment.

Alfa Laval PureBallast 3 has temperature and level sensors that bypass PLC, so even in case of PLC malfunction, signals won't be missed. The control panel monitors major components, gives feedback to show valve positions and is hard-wired to shut down in case of overheating or low water levels. Whatever goes wrong, your people and equipment are safe.

9. Is your ballast water treatment system automatic and easy to operate?

As onboard systems increase in number and complexity, crew availability and competence are not. This makes automatic operation essential for your ballast water treatment system.

A one-button start and stop, without the need for manual intervention during operation, saves time and means instant shut-down if necessary.

An intuitive graphical user interface offers a clear overview, letting your crew make informed decisions quickly. And graphical communication rather than strings of text makes it easier for international crews around the globe to use the panel with less risk of human error.
A control system that can stand alone or integrate into the Ship Control System gives added flexibility.

Make sure your system can deliver on these points.

10. Does your system's supplier have demonstrated capabilities?

Installing a ballast water treatment system is a complex undertaking, especially in retrofit scenarios. Many suppliers and subcontractors are involved, and delays due to poor project management or lack of experience can be extremely costly.

The ratification of the BWM Convention means all vessels are required to install a ballast water system within a few years; thousands of vessels will be competing for limited resources.

A reliable supplier will be able to prove their ability to deliver on time, work with many suppliers and have a positive installed base track record. As important as newbuild installation is proven expertise in retrofitting, which is more complex and challenging.

Your supplier should be a large enough player to have the production strength to scale up in the coming years and be able to prove their project management credentials.

Don't let your installation be a learning experiment for an inexperienced supplier.

11. Is your system accompanied by a strong global service offering?

Make your choice with the future in mind. A good ballast water treatment system should last the lifetime of your vessel.

Any supplier you consider must be able to provide you with good quality spare parts and the expertise and availability to deliver fast, anywhere in the world.

A global network of experienced and well-trained engineers, compliance expertise and the ability to advise on optimization and expansion issues is vital. A service offering specifically for ballast water treatment will prevent one-fits-all advice and costly mistakes.

Documented proof of a recognized supplier with worldwide support may also positively influence resale prices and the number of potential buyers.
If the vessel is sold down the road, having a system from a recognized supplier with worldwide support may also positively influence the sale price and the number of potential buyers.