Fouling Removal

During normal operations, many systems can become contaminated by bacteria or marine life. These issues are typically controlled through continuous biocide dosing from electrochlorination units, or by scheduled treatments using glutaraldehyde or THPS.

However, electrochlorination units can fail or microorganisms may develop resistance to commonly used biocides, allowing bacteria and marine organisms to establish and foul the system over time.

Fouling can lead to problems ranging from localised corrosion that weakens pipe walls to complete blockage of cooling-water flow paths. Removing fouling from the system is essential to prevent these issues and avoid costly downtime.

SANCCUS Solutions

The treatment process depends on the type of fouling:

Bacterial Fouling

Bacterial Fouling is treated with an approved broad-spectrum biocide applied at a shock dose designed to efficiently eliminate bacteria. Ideally, a biocide different from the one routinely used in the system should be selected to overcome potential bacterial resistance.

The biocide is applied at the specified dose and allowed to contact the system for the recommended time. After treatment, the system should be drained, flushed and Chemically Cleaned before returning to service.

Macrofouling

Macrofouling - sulphate-based fouling caused by marine life - is treated in several steps, beginning with a high-dose biocide approved to target the specific marine organisms present. The biocide should remain in contact for the prescribed time.

Following biocide treatment, any remaining hard shells or deposits may require an acid-based dissolver to remove carbonate-rich cemented material on internal surfaces. The system should then be flushed at high velocity to clear dislodged shells. For residues that do not respond well to high-velocity flushing, Debris Removel Gel can be used for safe and effective removal. As with the Bacterial Fouling treatment, the system should be Chemically Cleaned before returning to service.