Surface treatment

Efficient microbiological monitoring for surface treatment

Microorganisms – a real issue in surface treatment

Water consumption from the surface treatment baths (ex: car industry) is a large part of the global water consumption in an industrial plant. Microbiological contamination in the different baths can lead to quality problems: increased thickness (anticorrosion coating), surface defects… Nowadays each bacteriological crisis can generate an additional cost of 15k€. This additional cost must be multiplied by the number of crises per year and by the number of plants undergoing this kind of problems.

Since lead-free cataphoresis products are used, many production plants are confronted to periodical increases of cataphoresis consumptions which imply a progressive increase of deposited paints. Because this drift is possibly due to bacterial proliferation in the bath, bactericide treatments must be used more and more often.

Fast detection of microbiological drifts in the different surface treatment and cataphoresis steps is the key to efficiently monitor the installation at lower cost.

Problems due to microbiological contamination in surface treatment are:

1. For the process:
   • pH decrease in sensible steps (tunnel treatment of surface rinsing,  refiner, cataphoresis)
   • decrease in active molecules concentration (refiner, cataphoresis)
   • conductivity modification (cataphoresis)
2. For equipments:
   • pressure loss in filtrating media (resins, pouch filters…)
   • clogging (baths, wash racks, exchangers…)
   • creation of anaerobic zones which can lead to corrosion
3. For humans:
   • irritations
   • odors
   • infections

Concerned organisms are: bacteria, fungus, algae and yeast.

Industrials need a fast and quantitative measurement tool to precisely assess bacterial pollution in all types of liquid samples. The aim for industrials is to anticipate drifts and be responsive to prevent quality problems, additional costs, to fast validate treatments efficiency and choose the best moment to start again production safely.

Quench-Gone™ technique – fast, easy and precise microbiological measurement

The 2^nd generation ATP-metry kits enable measuring in few minutes the whole living flora in collected samples. The Quench-Gone™ kits - QGA™ and QG21I™ - allow quantification of microorganisms through the measurement of Intracellular Adenosine Triphosphate (cATP) – the energy carrier of any living cell. Intracellular ATP (cATP) is the true indicator of the concentration of all living microorganisms in the sample – bacteria, fungus, yeast, moulds, protozoa– which can be found in industrial process water, surface treatment baths, cataphoresis baths and UF-Rinsing baths. 

With the QGA and QG21I kits you can establish a biological mapping of your installation and monitor the microbial contamination in any type of water. Recommended critical points to monitor in surface treatment and cataphoresis lines are:

1. demineralized water production and stock
2. storage tank delocalized from the production area
3. last rinsing steps in surface treatment
4. dripping downstream the rinsing step
5. cataphoresis bath
6. the first UF-Rinsing

This technique allows industrials working in surface treatment to identify pollution origins, quantify this pollution and relate the pollution drift with the cataphoresis layer increase.

Benefits of using the QGA and QG21I kits in surface treatment:

1. Instantaneous indicator of microorganisms concentration in the installation.
2. Quantification of the real living flora in aqueous baths: cultivable or non cultivable microorganisms responsible of water quality degradation, surfaces treatment and painting by cataphoresis degradation.
3. Immediate information about the contamination in degreasing, rinsing or cataphoresis baths – result in 3 min. 
4. Early detection of water quality degradation = ALARM.
5. Localization of critical points for development of biomass in the different baths.
6. Localization of the microbial contamination origins (industrial water, demineralized water).

Benefits for the operator are:

1. Better installation knowledge and monitoring.
2. Optimization of treatments: monitoring of set up treatments efficiency; rectification of treatment actions, if necessary, and immediate validation of new treatments.
3. Reducing water use.
4. Reducing biocides use: reducing quantities if possible and treatment costs.
5. Less industrial effluents.