Despite their history of successful use as fuel system disinfectants and fuel preservatives, antimicrobial pesticide use faces increasing restrictions due to both regulatory control and public concerns. A variety of non-chemical treatments have been used with varying degrees of success to disinfect non-fuel fluids and to at least partially inhibit biofilm development on infrastructure surfaces. Promoters of one technology have claimed successful fuel disinfection and fuel-tank fouling prevention. This paper will review a range of non-chemical treatment technologies and will present the results of preliminary evaluations of several technologies that were tested on Jet A fuels that had been challenged with either Pseudomonas aeruginosa or Hormoconis resinae. Data are presented on treatment impact on adenosine triphosphate (ATP) concentration, culturability and live/dead direct counts in Jet A-1 and on glass microcosm surfaces.
Several of the major points that I made in 1995 need further consideration, based on both changes in the regulatory climate and field experience with microbial contamination control in surface transportation markets.
Smaller retailers depend on the expertise and reputations of their suppliers. Traditionally, refiners' attitudes about fuel were that if it met specifications at the time of sales, but failed later, the problem belonged to the owner at that time. As we begin to see impact of the Clean Air Act-driven fuel reformulations, increased consumer awareness and increased susceptibility to contamination, all market participants are going to have to cooperate to ensure that the customer with the engines gets consistently good fuel.
Adenosine triphosphate (ATP) assays have been used to quantify bioburdens (biomass) in low-organic-compoundcontent fluids (freshwater, seawater, cooling tower water, and similar fluids) since the early 1950s. The original methodology was labor intensive and required considerable laboratory skill. Over the past half-century, the protocol has been simplified substantially, but until recently, chemical interferences made it impractical to use the ATP test in metalworking fluids (MWF).
Quantification of adenosine triphosphate (ATP) in fuels and fuel-associated waters was first presented at the Technische Akademie Esslingen 6th International Fuels Colloquium in 2007. At the time, two issues limited the overall usefulness of ATP as a test parameter: inability to differentiate between bacteria and fungi and inability to detect dormant microbes.
Three alternative, non-conventional test methods are evaluated for their ability to detect and quantify bioburdens in fuel and bottom-water samples. Two of the parameters, catalase activity and adenosine triphosphate (ATP) concentration have been used previously. This is the first report of the use of fluorescence polarization (FP) technology for fuel and fuel-associated water testing.
In August, 2012 a member of the LinkedIn Metalworking Fluids Group asked for a recommendation for the best biocide/fungicide package to be used to protect a semisynthetic metalworking fluid from biodeterioration. His posting has generated nearly 50 responses. Some of the suggestions were clearly based on limited experience; experience with few MWF, a limited number of MWF systems or both. I posted a number of comments to the string and have compiled them in this article.
Industrial lubricants are increasingly providing a rich environment for microbial growth and proliferation. Most of the knowledge of lubricant biodeterioration has been extrapolated from field and laboratory experience with metalworking fluids. Compositionally more complex than most lubricants, metalworking fluids are either solutions or emulsions of 5 to 10% coolant concentrate in water.
As industry seeks to improve the economy of plant operation, responsible managers are paying more attention to factors that affect efficient and reliable operation of their facilities. One area of attention that can payoff handsomely is the control of microbiological activity in coolant systems. Many engineers and plant operations personnel are just beginning to appreciate the effects on their machining operations caused by their plant "biosphere," which contains bacteria, fungus, mold and other contaminants.
Mounting concerns over operational and waste management costs, as well as the quality and safety of the work environment have provided increased impetus for both formulators and end-users to strive to improve coolant life. There are a number of alterative approaches to achieving this objective. In this paper, the concepts of bioresistance and biostatic are defined and compared.
This case study reports culture and acid-fast bacteria direct counts from 99 MWF samples received for microbiological testing at Warren, Mich.-based Biosan Laboratories between December 2006 and September 2007.
All metalworking-fluid formulations share the common problem of susceptibility to microbial attack. This is not all bad news, since we need the used dilute fluid to be biodegradable for disposal purposes.
During the past decade we have witnessed a tumultuous debate over the disease risks posed by microbes that inhabit metalworking fluid (MWF) systems. Not infrequently, that debate has occurred in the absence of satisfactory data.
Root cause analysis is the process used to identify the fundamental cause for an undesirable condition. Premature filter failure due either to plugging or other mechanism is generally perceived to be an acute problem.
Since there are no microbial standard for the fuels, microbial contamination remained undetected inless sli9me started to plug the filters.
An array of microcosms containing California Air Resources Board (CARB)-compliant, oxygenated S7-octane gasoline over nutrient-amended water was monitored over a 7-month period. The array included tiplicate microcosms of each of four conditions:
Microbes in Fuel Retailing was the last in my series of NPN articles. In it, I presented a more global perspective on the key issues that I had addressed in earlier articles. Since 1999 there have been some watershed changes in the industry since it was written. The most important ones all involve dramatic changes in fuel product composition.
· Fuel Systems
Although the documentation of fuel biodeterioration dates back to the late 19th century, general recognition of the value of microbial contamination control evolved slowly until the 1980's. Since the early 1980's a number of factors have converged to stimulate greater interest in fuel and fuel system biodeterioration.
Adenosine Triphosphate (ATP) is an excellent biomarker present in all living cells. During the past several years, several ATP test methods have been developed to overcome interferences that have historically made ATP testing of fuels impractical.
Metalworking fluids provide an excellent environment for the growth and proliferation of a variety of bacteria and fungi. Historically, the incidence of infectious disease outbreaks at metalworking facilities has been rare. Consequently the primary focus of microbial contamination control efforts has been to prevent fluid biodeterioration.
Between 1994 and 1999, I had the opportunity to write a series of articles for National Petroleum News (NPN). Each article focused on one aspect of the connection between microbial contamination and operational problems in fuel retail systems.