Mic

MIC

Products and machines made of steel have long been considered to be solid, strong, and very durable. The effects of general corrosion, "rust", were considered to be the only factor limiting a steel product's ability to last forever. It is thought that the general corrosion of steel is recognizable and its effects are easily limited by the application of various coatings and paints. Only in more recent years have the destructive effects of Microbiological Influenced Corrosion, "MIC" been discovered. Today MIC, whether it is on the bottom of a barge, in a water pipe, or in a nuclear power plant's cooling tower, has evolved into a billion dollar problem.

To cure this problem, I have created a device that cleans MIC out of the bilges of barges operated on the Mississippi River system. The bilges or confined void spaces have never been able to be cleaned due to the extremely tight or inaccessible area in which you would have to work. I found that most barges have a coating on the steel which provides a food source that the MIC bacteria absorbs (eats) and the bacteria's resulting acid actually can penetrate the steel barge. Businesses that clean these barges to rid them of the MIC and the organic coating can charge as much as $10,000 to do just the ends of the barges, which is an area less than a tenth of the entire barge. The inner bottom void spaces which take up the remainder of the barge's area are only 15" high, 27" wide, and 28' long. Some barges have as many as 90 of these confined spaces, and none of them have been cleaned because their limited size makes them inaccessible. With the completion of my product it will be the first time the inner bottom void spaces of a barge can be cleaned. This will mean the MIC and its food source, the organic coating; will be

completely removed from the barge for the first time since its original construction at the ship yard.

For many years, MIC was incorrectly identified as the corrosive effects of saltwater on steel in ocean going vessels. Although salt certainly does have a corrosive effect on steel, it was not until more recent years that the term MIC was originated, and its effects are only starting to be discovered. MIC is responsible for the accelerated corrosion in ocean going ships, water storage tanks, fire protection sprinkler systems, commercial and military aircraft, and most recently discovered affecting the inland river barge fleet.

MIC is a type of corrosion which is identified by single celled micro-organisms such as algae, fungi and most commonly bacteria (Smart 57). The presence of bacteria in low oxygen or even anaerobic conditions with the most fundamental nutrient source can allow for the colonization of bacteria and result in MIC. "The water environment can be free flowing, stagnant, fresh, brackish or salt" (Jeffery 1). "Contrary to general corrosion, MIC corrosion is highly localized and the rate of corrosion can be extremely rapid, resulting in the 100% penetration of heavy gauge steel pipes or plates in just a few months" (Smart 60). Bacteria live synergistically, assisting each other, and when consuming the nutrient source the bacteria excrete acids which are highly corrosive and can destroy certain components of the steel (Chemtex 2). This results in the degradation of the steel. Prohibiting or limiting the destructive effects of MIC, requires a very thorough understanding of the

various organic chemical reactions, all occurring within an area visible only through a microscope.

It is said that there are about thirty five thousand barges in the US. The average barge comes out to be close to three hundred and fifty thousand dollars for the purchase price. Multiply those together and that is the value of the barge assets in the US. That staggering amount is over twelve billion dollars. MIC is most commonly found in the wing tanks of the barges. Although it takes awhile for the MIC to eat through the 5/16"-1/2" steel, the affects are the same in that it eats holes though the steel. Pits in a ballast tank of a ship have reached six inches in diameter (Smart 3). If a boat is taking on water it is an extremely