• NEI Ballast Tank Protection Brochure
• Video Illustration of VOS System

The Problem

Biology

Over the last 50 years there has been a significant increase in the size and number of vessels involved in international shipping. In addition to cargo, these vessels transport large quantities, often thousands of tons, of water as ballast to maintain proper buoyancy and stability. To load cargo, ballast water is pumped out of the ship. The aquatic organisms transported in the ballast water are introduced into this new environment. These biological invasions have resulted in infrastructure damage, toxic algal blooms, and the collapse of native coastal fisheries. As shipping has increased, so has the number and severity of ballast-water related biological invasions.

The most devastating aquatic nuisance species, the zebra mussel was first discovered in the Great Lakes near Windsor, Canada in 1988. It was transported there in the ballast of a vessel arriving from the Black Sea. The effort to stop the spread of this mussel now costs Canada and the US (primarily utilities) hundreds of millions of dollars annually. Although the Great Lakes were initially the focal point for this issue, there are now thousands of similar stories around the world.

To limit the potential for future invasions, pending international regulations will require globally-trading ships to install a ballast water treatment system to eliminate the introduction of ballast water-transported organisms into port ecosystems. Specifically, the International Maritime Organization (IMO) passed regulations in February 2004. Member maritime nations including the Norway, US, Canada, Japan, Australia and the EU countries are in the process of developing national regulations to enforce this new international law. The IMO web site www.imo.org provides additional information about this issue.

Corrosion

The inside of a vessel ballast tank is one of the most corrosive environments on earth. Water, particularly salt water, acts as a catalyst for oxygen to turn steel into rust:

Being that for the foreseeable future seafaring vessels will be made of steel, and water will be used as ballast, what can be done to decrease corrosion?

Since air is 21% oxygen, purging the air from ballast tank void spaces removes one parameter of the above equation.

The Solution

Technology

NEI has developed a patented ballast water treatment technology that is safe, cost-effective, and reliable. The system induces a low-oxygen (hypoxic) condition in vessel ballast tanks using inert gas. This limits the amount of oxygen available to form iron oxide, or rust. Simultaneously, the hypoxic condition significantly decreases the survival rate of aquatic organisms drawn in with the ballast water. This technology has been proven in Shipboard Trials to consistently meet the IMO Ballast Water Discharge standards.

The Venturi Oxygen Stripping™ equipment is integrated into a vessel's existing ballast system. Treatment begins as soon as ballast is drawn in.

Ballast water passing through a Venturi Oxygen Stripping™ system is subject to the following three elements:

• Caviation Mixing
• 95%Dissolved Oxygen Reduction
• Lowering of pH to 6.0

The physical treatment is complete before the water enters the ballast tank. Each of these elements contribute to the system's effectiveness.

Biological Solution

Shipping lines are challenged by the need to balance their safety and economic concerns with the need to mitigate the introduction of harmful invasive species. Rapidly evolving ballast water treatment regulations may seem to present an obstacle to addressing these concerns.

While other ballast treatment methods have demonstrated varying degrees of effectiveness, many technologies create problems of their own.

For example, they are:

• Too Dangerous
• Too Large
• Too Expensive

Venturi Oxygen Stripping™ is a safe, compact and effective ballast water treatment system that enables shipping lines to lower vessel operating costs.

Dissolved oxygen is lowered to an hypoxic treatment level in less than 10 seconds. The physical treatment is complete before the water enters the ballast tank. Biological treatment begins immediately as the ballast tanks fill with deoxygenated water.

Corrosion Solution

Using the same low-sulfur inert gas used in the Venturi Oxygen Stripping™ biological treatment step to blanket ballast tanks as they drain, oxygen levels are maintained below 0.5%.

The International Association of Classification Societies (IACS) Guidelines for Coatings Maintenance and Repairs describes protocols for ballast tanks surveys. The Guideline calls for surveyed ballast tanks found to be in FAIR or POOR condition to be restored to GOOD condition. As ships age, this restoration becomes increasingly expensive, running into the millions of dollars. NEI's ballast tank deoxygenation system is designed to maintain a GOOD rating throughout the life of the vessel without any need for coating restoration or steel renewal.

BALLAST TANK MAINTENANCE COSTS ARE REDUCED TO PRACTICALLY $0