Preventing the growth of microorganisms in water-miscible metalworking fluids in centralised maintenance systems

Microbial contamination in water-miscible cooling lubricants (wmKSS) must be avoided, as above a certain level the cooling lubricant 'tips over' and becomes unusable. It then has to be disposed of, which causes considerable costs and production downtime.
To avoid this, various biocides are used to inactivate all microorganisms. Very different substances are produced and offered by the chemical industry. A cost-effective method is to set the pH value to 9.5, as microorganisms no longer grow at extreme pH values.
What people often do not realise is that microbial resistance can occur in a closed cycle over a long period of using primarily organic biocides. A special mechanism that develops in parallel is biofilms - a special method of resistance formation of microorganisms that protects microorganisms in the biofilm. As hardly any organic agents can penetrate through the polymer structure (EPS) of the biofilm.
One effect that also occurs is the formation of nitrite, which causes a lowering of the pH value. However, if the pH level is lowered, growth is possible again. Biocides are therefore also necessary to prevent the wmKSS from tipping over.
A number of chemicals are frowned upon due to insufficient effect or side effects. Isothiazolinones with various substitutes are often used today. These are highly effective - but very expensive and toxic to the environment, humans and are not biodegradable.
If the coolant is split into water phase and oil phase, the oil phase is recycled - but the water phase is often neglected and not cleaned, as it is expensive. Here, Bioway has proposed and evaluated new methods that include cost-effective splitting with purification of the water phase to around drinking water quality - COD 30 mg/l.
A new solution from Bioway goes back to initial tests carried out around 15 years ago. This method replaces the organic, expensive biocides and uses electrolysis instead. The advantage of this method is the plurality of effects that occur. The biocide here is inorganic in ionic form and therefore more effective due to faster kill kinetics. This also means that biofilms are better penetrated.
The accompanying physical side effects form a positive synergism and reinforce the inactivation of all microorganisms and viruses. Inactivation is not achieved by extreme pH values coupled with organic biocides, but by ionically present biocides, which slowly decompose back into the original substances of the water after the current is switched off.
The particular advantage of the electrolytic method is the precise control of the concentration of disinfectants over time, as these are formed in direct proportion to the current intensity. Incidentally, it no longer has to be a strongly alkaline pH value of over 9 - the technology works excellently at a neutral pH value.
Another positive effect is the prevention of anaerobic environments. Oxygen is released, nitrite oxidises to nitrate and the formation of putrefactive gases is prevented. This also serves to maintain the technical quality of the cooling lubricant.
This process was tested for stability over a long period with wmKSS and subjected to an electrolytic test at the EPFL / Lausanne - Switzerland.

In summary, the advantages are as follows:
- Significant cost reduction, as expensive organic biocides are substituted
- No accumulation / handling of toxic biocides
- The water phase can be easily treated
- Multiple effects of electrolysis - thus better, faster kill kinetics
- Better penetration of the EPS structure of biofilms - Prevention of biofilm formation
- Oxidation of nitrite to nitrate - prevention of nitrite formation
- No formation of resistance - as with organic biocides
- Works in slightly acidic, neutral and alkaline medium / emulsion
- Precise dosing of the disinfectants over time - as these are formed in direct proportion to the current strength

Bioway Consulting SL , ES-03750 Pedreguer / Alicante;
C./ Tirant Lo Blanc 4, office 19 - Spain
VAT N°ESB75242230
Norbert Pautz - Managing Director
www.biowayconsulting.com; Phone:0034685424040
Mail: contact@biowayconsulting.com

Bioway has been in existence for almost 40 years and was founded as a sole proprietorship in Germany. A limited liability company was established in Switzerland with a subsidiary in Germany and later as a private limited on shares in Cyprus. Now since November 2024 Bioway Consulting SL is incorporated
Bioway deals with electrolysis-based wastewater treatment technologies, incorporating complementary technologies such as membrane filtration. Furthermore, a system for air purification / disinfection was developed to inactivate infectious biological particles such as viruses and bacteria.
Bioway works as a consultant mainly in D, A, CH - German-speaking countries, whereby new technologies are further developed and sold on the market in co-operation with system manufacturers.
The main task is to advise customers, solve problems, implement technology to solve tasks and sell systems / equipment for the purification of liquids (e.g. cooling lubricants) and industrial waste water. R & D takes place in an own laboratory is Spain.

This release was published on openPR.