Erma First: Full-flow electro-chlorination BWM systems hands-down winner in spot trading

Full-flow electro-chlorination ballast water management technology is more effective than ultra-violet technologies or side-stream ballast water systems and systems without filters, according to a white paper released by Erma First.

The ballast water management system manufacturer said its research focuses particularly on the needs of the spot trading cargo fleet, which trades in a range of waters and is potentially subject to both US Coast Guard and IMO standards.

The white paper reviews design and system design limitations for different technologies and their implications on CAPEX, OPEX and installation complexity.

According to the shipbroker Clarksons (August 2020 BWTS Report), 46% of the world’s merchant ships have installed electro-chlorination and 25% ultra-violet systems.

As explained by Erma First, BWM systems using filtration are the established majority because cyclonic separators, membranes, and mechanical filters are needed to remove larger than 50 μm organisms that are resistant to disinfectants and UV radiation. In electro-chlorination technology, filtration is the only way to achieve optimal use of power during operation.

In line with the D-2 Ballast Water Performance Standard, treated and discharged ballast water must have fewer than 10 viable organisms greater than or equal to 50 micrometers in minimum dimension per cbm. It also needs to have fewer than 10 viable organisms less than 50 micrometres in minimum dimension and greater than or equal to 10 micrometers in minimum dimension per millilitre.

Furthermore, the company pointed to the limitations of UV treatment systems as suspended solids and particles in the water can interfere with the light energy transmission and impact the exposure of organisms to UV light, a key requirement for energy emitting lamps to perform their task.

The white-paper further indicates that UV systems require large power requirements of ultra-violet lamp-based systems, placing limits on ship cargo operations.

The company added that side-stream ballast water management systems impact ships’ cargo-carrying capacity due to the need to carry salt water, as well as compliance risks on systems with the absence of filtration stage.

“The inherent flexibility of full-flow electro-chlorination makes it a hands-down winner for the spot trading shipowner,” says Konstantinos Stampedakis, Managing Director of Erma First.

“The salinity and clarity of the waters in which a vessel is trading affect the ability of a BWMS to work properly. A spot trading vessel needs to be able to meet all global and local ballast water requirements, including the USA. A full-flow electro-chlorination system, backed up with filtration, can handle large volumes quickly with low power consumption. It doesn’t take up vital cargo space and can be installed in a timely and cost efficient manner. ”

The Ballast Water Management (BWM) Convention entered into force on September 8, 2017. The United States Environmental Protection Agency (EPA) had adopted a similar regulation for ballast water treatment which became effective on January 1, 2016.

Under the rules of the IMO convention, all ships engaged in international trade are required to manage their ballast water so as to avoid the introduction of alien species into coastal areas, including exchanging their ballast water or treating it using an approved ballast water management system.

Initially, there will be two different standards, corresponding to these two options.

The D-1 standard requires ships to exchange their ballast water in open seas, away from coastal waters.

D-2 is a performance standard which specifies the maximum amount of viable organisms allowed to be discharged, including specified indicator microbes harmful to human health.