Assessment of biocides and ultrasound treatment to avoid bacterial growth in diesel fuel

• We assessed biocide treatments to avoid microbial growth in diesel storage tanks.
• Biocides must be selected after experimental evaluation of the contaminated system.
• Most microbial growth takes place in the aqueous phase.
• Free water phase in tanks must be avoided to prevent microbial growth.

Prevention and avoiding growth of microorganisms inside fuel storage tanks is a major concern for the oil industry because the associated problems caused by corrosion, plugging and blockage in storage and dispensing facilities. To effectively control microbial growth in petroleum fractions, assessing new treatments and acquiring deepen knowledge about existing treatments must be performed. In the present work, we compare and evaluate the efficiency of several chemical and physical treatments on the growth of microorganisms found in real samples of diesel fuel from different storage tanks from petrol stations in Spain. The treatments include the use of ten organic biocides with different functional active groups, hydrogen peroxide and ultrasounds. The better results were obtained with water-soluble biocides, especially those with an oxazolidine group in the active compound, although the effectiveness of different biocides very much relies on biodiversity and physicochemical properties of the media.