

Cooling Water Treatment

An effective water treatment programme maintains the cooling efficiency and prevents fouling of the system. To meet this objective, cooling water treatment technology is concerned with preventing:

  • Scale forming or corrosion
  • General fouling, sediment etc.
  • Microbiological fouling/Biofilms control of waterside conditions is achieved by the correcy application of MASOL treatments and the maintaining of the necessary control parameters.

From a sample of mains and system water, we determine if the water is predominately scale forming or corrosive (by the Langelier Saturation and Ryznar Indicies). Our selection of products will be based on the results of this analysis.

In addition to scale, fouling and corrosion, recirculating industrial cooling water systems, particularly open evaporative systems, provide a favourable habitat for the growth of a wide range of micro-organisms. Such systems obviously fulfil the primary requisite for biological activity; the availability of water and certain environmental factors, such as temperature and pH can be near ideal for the development of many types of bacteria, algae and fungi.

Microbial Populations

Cooling systems harbour two distincy microbial populations:

  • Planktonic: Micro-organisms present in the recirculating water. (Free Flowing)
  • Sessile: Micro-organisms growing on the surfaces within the system causing Biofilm formation (Surface-attached).

In aquatic systems the predominant bacterial form is SESSILE (Biofilm formers). Bio films are the natural form of Bacterial growth. A biofilm can be defined as a physiologically co-ordinated community of Bacteria and other micro-organisms, embedded in a protective film (Glycocalyx) which traps organic and inorganic debris within it, giving a source of food and protection for Bacteria.

In complete water treatment schedules a biocide programme should be incorporated and monitered to ensure that the biocides are controlling bacterial growth effectively. To maintain a clean safe system a Biocide programme will generally use two biocides in an open evaporative system. This prevents resistant strains proliferating. The main biocide should be one that is effective against sessile bacteria as this is the predominant bacteria in the water.

Legionella bacteria are associated with this biofilm and it's control is vital in limiting proliferation.

Closed Cooling Systems

In closed cooling systems bacteriological control is also very important, especially with regard to Pseudomonas bacteria. If Pseudomonas and other bio-film forming micro-organisms contaminate a system and multiply, they will form a microscopic jelly-like film aroun the inside of the pipes. These anaerobic conditions protect an enhance the growth of sulphate reducing bacteria between the film and the pipework, leading to microbial corrosion. Left unchecked the film will increase and debris will accumulate, slowing down the water flow through the system and creating clogging of small bore control valves and fittings. At the same time the corrosion will proceed until eventually leaks occur.

We have a wide range of MASOL products specifically for biocide control including Legionella and Pseudomonas bacteria. Alternative methods of biocide control are available utilising chlorine dioxide, UV equipment and oxiding reagents (Bromine and Chlorine etc).