Filtration + UV versus other ballast water treatment technologies

Shipboard BWMS fall largely into systems that use no active substances (commonly filtration plus UV) and systems that use active substances (commonly electrochlorination or chemical dosing). PACT Marine’s published shipboard architecture is filtration plus medium-pressure UV.

This article does not rank manufacturers. It sets out the engineering differences that matter when selecting a treatment principle for a vessel or a port.

This article is general information. It is not vessel-specific regulatory, class or legal advice. Requirements vary by vessel, flag, class, voyage and operating area. Confirm current primary sources before relying on any statement.

Filtration plus UV

No chemical is added to the tanks. Holding-time and neutralization requirements associated with oxidants generally do not apply. The trade-off is electrical load, sensitivity to UV transmittance, filter behaviour in high-sediment water, and the need to keep lamps, sleeves and intensity sensors inside their maintenance interval.

Electrochlorination and chemical systems

These systems generate or dose an oxidant and typically require neutralization before discharge. They can have different holding-time, salinity and temperature envelopes. They introduce chemical handling, TRO monitoring and, in some cases, different hazardous-area considerations. They are not discussed here as a product offering.

Port and shore-based treatment

A vessel-mounted BWMS is not the only way to manage ballast. Ports, terminals and yards can consider reception and shore-based treatment for contingency, non-operational shipboard systems, or as infrastructure in its own right. That is a different engineering problem — peak flow, berth configuration, residual sediments and instantaneous treatment — and should not be specified from a shipboard data sheet.