Microbial challenges for domestic heating oil storage tanks

Microbial growth on hydrocarbons is common in nature and used in bioremediation of contaminated sites, whereas in fuel storage tanks this phenomenon can affect the stability of the fuel and the tank. The impact of microbial growth and produced metabolites on materials, which are used in the construction of storage tanks, were analyzed. In contrast to metal tank components, polymeric materials did not affect or were influenced by microorganisms. Zinc was highly corroded by microbial growth, most likely due to the formation of organic acids that were produced during microbial growth on hydrocarbons. A contaminated water phase in a storage tank of a heating system was simulated with a self‐constructed pump test bench. Microbial growth began in the water phase of the storage tank and microbes were distributed throughout the tank system, through water‐in‐oil microemulsions. No microbial growth was observed in oil that was previously contaminated, indicating that essential nutrients had been depleted. The identification and removal of these essential nutrients from fuels could minimize or prevent microbial contamination. The results are discussed with regard to developing recommendations for the design and operation of domestic heating oil storage tanks to lower the risk of technical failure due to microbial contamination.