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Biocide

In most cases a conta­mi­nation of technical systems and under­ground storages with micro­or­ga­nisms is a risk for safe operation and can quickly lead to technical problems or loss in quality.

The selection of a suitable treatment strategy is often crucial for the further operation of technical systems. The basis for this should be a qualified micro­bio­lo­gical expert’s assessment taking important process parameters into consideration.

To estimate the effec­ti­veness of biocides under specific condi­tions for use (e.g. tempe­rature, salt content, type of infection) MicroPro GmbH uses classic micro­bio­lo­gical, bioche­mical and molecular inves­ti­gation methods.

We offer you:

  • Qualified micro­bio­lo­gical and molecular biology investigations 
  • Deter­mining the bacteriostatic/bactericidic effec­ti­veness of chemical formulations 
  • Deter­mining the effective concen­tration under specific appli­cation conditions 
  • Inves­ti­ga­tions on influence through parallel use of other chemicals 
  • Alter­native treatment strategies, recom­men­da­tions on system operation

Case histories:

Investigation of a biocide for use in injection water

Water samples from above-ground facilities for the interim storage of injection water of an oil reservoir were micro­bio­lo­gi­cally examined to check the effec­ti­veness of the biocide used.

Enrichment cultures of bacteria of relevant physio­lo­gical groups were treated with different biocide concen­tra­tions under condi­tions close to practice and the bacte­riostasis and bacte­ricidy of the formu­lation were deter­mined. It was found, that the already used biocide concen­tra­tions only slowed down bacterial growth too insuf­fi­ci­ently and that clearly higher biocide doses or an alter­native biocide was required.

Apart from this, the commercial rapid-tests used at field station to determine sulphate reducing bacteria (SRB) were compared to the laboratory analyses. Here, it had to be deter­mined that the rapid tests, after proof of lower, but critical germ content, failed, and only worked from relatively high bacteria popula­tions onwards. Alter­native test methods were suggested.

Biocide treatment of caverns

 The operation of numerous caverns has been guided with micro­bio­lo­gical inves­ti­ga­tions by MicroPro GmbH for more than 40 years. Several of these caverns indicated an initial micro­or­ganism population after solution mining.

In the early 1970s, the micro­or­ganism population of one cavern was exter­mi­nated successfully with a self-developed biocide formula. Repeated analyses of the subse­quent years proved effec­ti­veness of this treatment. At the end of the 1990s an increase in population with sulphate reducing bacteria (SRB) was found again.

Based on a recom­men­dation of MicroPro GmbH, treatment of the 40.000 m³ cavern was carried out with a salt water soluble biocide in 1999. The inves­ti­ga­tions in the subse­quent years, the most recent one in 2010, indicated that the brine has remained free of germs after this treatment and thus confirm the treatment concept in its immediate effect as well as being a form of long term protection.

Biocide treatment of an underground gas storage

A population of sulphate reducing bacteria (SRB) was proven in the above-ground facilities of a gas storage unit. There was an increased risk of corrosion here through sour-gas formation. The systems were subjected to an annual, prophyl­actic treatment with biocides for this reason. After consulting the customer, 5 biocides available on the market at the time were selected to examine their effec­ti­veness compared to the SRB populating the storage unit. 

Bacte­rio­static and bacte­ri­cidic concen­tra­tions of each of the selected biocides were deter­mined with enriched bacterial culture from the system and a corre­sponding recom­men­dation for carrying out the disin­fection was provided.