With the Ballast Water Management Convention soon entering into force, shipowners will be required to comply with either D-1 (ballast water exchange) or D-2 (ballast water treatment) standards until such time as it is required that they comply only with the D-2 standard. New build vessels must install ballast water treatment systems if constructed on or after the Ballast Water Management Convention entering into force. For existing ships, shipowners are required to install a ballast water treatment system at the time of its International Oil Pollution Prevention (IOPP) survey on or after September 8, 2019.

In our previous article, we have listed which vessels the Ballast Water Treatment solution applies to. Find the list here.

What is Ballast Water Treatment?

Ballast water treatment is the process of treating ballast water in order to actively remove, kill and/or inactivate organisms prior to discharge. Ballast water treatment is different from the older process of ballast water exchange, which involved completely flushing the ballast water tanks during voyages.

What are the Ballast Water Treatment Standards?

Ballast Water Treatment Standards are set by IMO Regulation D-2, which establishes numerical limits for different size classes of organisms that may be released in specified volumes of water.

  • In the largest organism size class (organisms greater than or equal to 50 micron) vessels must discharge less than 10 viable organisms per cubic meter.
  • In the mid-range (organisms less than 50 micron and greater than or equal to 10) vessels are required to discharge less than 10 viable organisms per milliliter.
  • Specific concentrations of indicator microbes are set for the smallest size organisms (smaller than 10 micron).
ERMA FIRST Ballast Water Treatment

ERMA FIRST is the first full flow electrolysis Ballast Water Treatment System worldwide. ERMA FIRST comes in two different types of Ballast Water Treatment Systems:


ERMA FIRST BWTS FIT is an advanced modular system that was developed to exceed all the special installation requirements either for New Building vessels or especially any retrofit project. Covering an extensive capacity range from 50 to 3000m3/hr and having completed successfully the required tests on the way to USCG approval, ERMA FIRST FIT is an ideal solution for all types of ships. The major components of the system are a high-end backwash filter and an electrolytic cell with outstanding performance under the most demanding conditions. The self-cleaning automatic screen filter has a nominal filtration rate of 40 microns. Its special designed screen provides with enormous zooplankton, phytoplankton and sediment removal, minimum pressure and uninterrupted, long-lasting operation at an extremely small footprint element. For the de-ballasting of the vessel there is no need to use the system; It is completely by-passed and the water can be discharged directly overboard, after neutralization where applicable, with considerable gains in energy saving for the operators/managers of the vessel. Using an active substance that is produced by the method of electrolysis, any danger for re-growth of microorganisms is eliminated.

The most important benefits of the ERMA FIRST BWTS FIT is that the Ballast Water Treatment System is:

  • Simple and Flexible
  • Suitable for all pump capacities
  • Suitable for all available spaces
  • Suitable for Fresh Water (0,9 PSU Salinity) and Low Temp. Waters (3oC)
  • Low Power Consumption in Various Waters (1,8 kW/100m3 at 30 PSU)

The ERMA FIRST BWTS is the industry’s standard system based on the most efficient filtration device, the multi hydrocyclones. The system uses an advanced filtration and cyclonic separation stage for the removal of large organisms and sediment in combination with an electrolytic cell for the production of free chlorine and the elimination of the remaining viable organisms. The pre-filter is efficiently removing large particles, having a very low pressure drop even in very high sediment uptake. The hydrocyclone is comprised of specially-machined disks, made of synthetic material, stacked vertically, incorporating mini-cyclone geometries that enable sufficient separation of micro-organisms and sediments larger than 20 microns, by using centrifugal forces induced due to the water movement inside it. The combined effect of fluid velocity and centrifugal forces enables separation of particles from water through an overflow stream and an underflow where sediments are draining back the ballast water origin. Thus, even in very dirty-sedimented waters, the hydrocyclone needs no backflushing and provide stable water flow at all times, with stable pressure drop surpassing clogging risks as associated with typical backflushing filters.

The most important benefits of the ERMA FIRST BWTS is that the Ballast Water Treatment System is:

  • Simple and Flexible
  • Low Maintenance
  • Extreme sediment removal
  • Low Pressure Drop of Hydrocyclones
  • Stable Flow Capacity at all Water Sediment Load Conditions
  • Very Low Associated Fuel and Operating Costs

For any inquiries or questions regarding the ERMA FIRST products and services, please contact us at marinesales@hansbuch.dk.


FAQs: ERMA FIRST Ballast Water Treatment System

Here you will find answers of the most common questions about the ERMA FIRST Ballast Water Treatment System.


Is the system IMO Type Approved?

ERMA FIRST Ballast Water Treatment System holds the IMO Final Approval, Type Approval and USCG AMS Acceptance.

Does it meet USCG discharge standards?

It is up to USCG to decide. But yes, the system is designed to meet USCG requirement. ERMA FIRST would not have submitted its application unless they felt sure it would pass.

Has ERMA FIRST submitted an application for USCG Type Approval?

Yes. The application was submitted April 11th 2017.

How does the ballasting operation work?

During ballasting, the water goes through the filter, where organisms and sediment (with a diameter larger than 40 microns for ERMA FIRST FIT and 20 microns for ERMA FIRST) are separated and further discharged overboard, to their original habitat. The filtered water is then entering the Electrolytic Cell. From the chlorides of the water, free chlorine is produced through the process of electrolysis at very low concentration (4-6 mg/L for ERMA FIRST FIT and 10 mg/L for ERMA FIRST). The treated water then, enters the vessel’s ballast tanks.

How does the de-ballasting operation work?

During de-ballasting, the system will only monitor the residual oxidants and will further intervene if necessary. The main stages of the system (filtration and disinfection) are bypassed. A chlorine sensor samples the residual chlorine at the discharge line. If this is greater than 0.1 mg/L, then it drives a dosing pump for the dosage of a neutralizing agent (Sodium Bisulfite). The successful neutralization of the free chlorine is confirmed by a second chlorine sensor, installed at the far end point of the ballast discharge line.

What are the power consumption?

ERMA FIRST operates as low as 1,8 kW/100m3 at 30 PSU Normal Seawater, and 6,3 kW/100m3 at 3 PSU Brackish Water. The biggest ERMA FIRST system operates 54 Kw/3200m3 at 30 PSU, and 180 kW/3200m3 at 3 PSU. Adding commodities or establishing a brine tank, can significant reduce the vessels power consumption when sailing in Low PSU waters.

What are the space requirements?

ERMA FIRST is a system with low footprint and limited space requirements. ERMA FIRST can be installed with various piping alternatives. The units can be installed horizontal or vertical,submerged or as a container solution. For vessels which has critical limited space, ERMA FIRST suggests the compact Filtrex filter.

What maintenance is required and what is the time estimate for maintenance?

ERMA FIRST filters have a lifetime of 5000 running hours. Depending on the vessel type and number of ballasting excises, the time frame for maintenance is individual for each vessel and the vessels trade. ERMA FIRST can create an operating expenses calculation, providing the ship-owner with an expected cost per vessel, providing a clear picture of the ship-owners investment.

For any inquiries or questions regarding the ERMA FIRST products and services, please contact us at marinesales@hansbuch.dk.