Prevention of microbiological contamination, the Dilurit® BC S-System - a contemporary in-situ biocide

In addition to the ubiquitous bacteria, legionella and pseudomonads are also the cause of various problems in water systems and thus contribute to the main concern in the industry.

A water-bearing system where there is poor microbiological control can lead to high financial losses and can also have a direct impact on the health of employees and third parties.

Kurita has a long history of controlling biofilm and micro-organisms in water and paper systems. Over the past few decades, Kurita Research has developed a complete biocidal product range with a wide antimicrobial spectrum.

To complete its wide product range, Kurita has developed an in-situ biocide system that is controlled and dosed by a dosing system specially developed by KURITA - the Dilurit^® BC S-System.

The Dilurit^® BC S-System is a fast-acting, easily detectable, oxidising biocide that decomposes into environmentally friendly inorganic compounds.

Dilurit^® BC S-System has high efficacy against:

• Slime-forming microorganisms
• Sulphate-reducing bacteria
• Legionella
• Algae
• Yeast
• Mould
• Filamentous bacteria
• Pseudomonas

Figure 1 shows an example of the efficacy against Legionella pneumophilia conforming to DIN EN 13623 and Pseudomonas aeruginosa conforming to DINEN 1276 under modified condition according to DIN EN 13623. The biocidal system was dosed in various concentrations to a defined amount of Legionella pneumophila and Pseudomonas aeruginosa bacteria culture. The graph shows the minimum concentration of the Dilurit^® BC S-System for a successful passing of the DIN EN 13623 or DIN EN 1276.

Kurita's advanced Dilurit^® BC S-System is a mild oxidising agent with a broad spectrum of activity, long-lasting efficacy and good compatibility with other process chemicals.

Figure 1. Proof of the effectiveness of the Dilurit® BC S-system conforming to DIN EN 13623 or DIN EN 1276

In operational trials, it was shown that the concentrations of Legionella and Pseudomonas have been significantly reduced when using the Dilurit^® BC S-System (Figure 2). The AOX value in the system could also be lowered compared to the previous biocide use (Figure 2).

Figure 2. Efficiency of the Dilurit® BC S-System

Besides the usual analyses, which include the determination of physical and chemical parameters in addition to microbiological investigations, the visual inspection of production lines and cooling towers remains an integral part of the assessment of biocidal treatment.

Figure 3 shows that the system is much cleaner using a Dilurit^® BC S-System-treatment than with the previous treatment.

Figure 3. Comparison of operational services of a system after four weeks of operation with (b) and without (a)
treatment with Dilurit® BC S-System

Another advantage, in addition to the emerging biocidal property, is that the Dilurit BC S system has no corrosive property. This is based on in-situ production using complex dosing technology. No free chlorine is formed and the oxidative, reductive potential is significantly lower than that of comparable oxidative biocidal agents.

Figure 4. Comparison of corrosion rate of different oxidiser in comparison to the system with the
Dilurit® BC S-System

Kurita’s team of experts has in-depth knowledge in the solution of microbiological problems. They also offer state-of-the-art dosing systems as well as online monitoring and control technology. All of Kurita’s biocides comply with national and EU regulations.

The Dilurit^® BC S-System manufactured in-house ensures that the active biocide is dosed at the optimal application concentration and online monitoring ensures there can be no underdosing or overdosing. This achieves an economical and efficient use and smooth plant operation.

The advantages of the Dilurit^® BC S-System are:

• Excellent performance in a wide pH range (pH 6 – 10), even under difficult conditions (neg. ORP system (oxidation / reduction potential, high conductivity)
• Modern dosing system: 100% conversion of the reactive components; very low formation of AOX (absorbable organic halogens) and THM (trihalogenomethanes)
• A very selective oxidising agent; no negative impact on process chemicals
• The Dilurit^® BC S-System does not undergo adaptations or population shifts.

The Dilurit^® BC S-System is ready to take on any challenge. No matter which aspect is considered. Be it the biocidal property, the question of occupational safety or one of the most modern dosing systems that monitors fully automatically and remotely, it produces an effective biocide system.

Read the article online at: https://www.hydrocarbonengineering.com/product-news/06072020/prevention-of-microbiological-contamination-the-dilurit-bc-s-system--a-contemporary-in-situ-biocide/