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Bio-Remediation-Managing Munching Microbes
By Ed Sunkin
The practice of using microbes to break down and clean up hazardous and unwanted chemicals has been used for many years. However, most people were first introduced to the practice of using oil digesting microorganisms in 1989, when television news broadcasts showed microbes being used in the cleanup of the Exxon Valdez spill, which deposited millions of gallons of oil along the shores of Prince William Sound, AK.
Nearly a decade after that environmental tragedy, specially developed microbes are being used today in automotive machine shops for parts cleaning and reducing waste disposal costs.
As this technology becomes more prevalent in the rebuilding industry, some shop owners may have questions regarding using microbes in their parts cleaning duties. According to the U.S. Environmental Protection Agency (EPA), bio-remediation is a treatment process that uses naturally occurring microorganisms or microbes to break down or degrade hazardous substances into less toxic or nontoxic substances.
Certain microorganisms can digest organic substances such as fuels, oils, grease or solvents that are hazardous to humans, animals and plants. Normally, these microbes break down the contaminants into harmless products, mainly carbon dioxide and water.
According to Greg Myers, sales manager for Steelabrator Cleaning Systems, San Antonio, TX, one reason for the interest in bio-remediation is driven by the continuing changes and stricter regulations governing solvents and aqueous cleaning practices. "Bio-remediation contributes to the industry’s move toward safer waste-minimization practices," Myers said. "The practice is an efficient and cost-effective way to reduce hazardous waste costs generated by machine shops."
Howard McCollom Jr., a sales representative for Graymills Corp., Chicago, IL, a manufacturer of bio-remediation cleaning equipment and products, said bio-remediation is a naturally powerful solution to parts cleaning savings. "Use of these systems can increase cleaning productivity, worker efficiency and lower waste disposal costs," McCollom said.
Bio-remediation products for the shop
There are a number of bio-remediation products and equipment available today for machine shops and small parts rebuilders. Most cleaning equipment offered today that incorporates bio-remediation technology is based on the sink-on-a-drum unit.
Myers said Steelabrator’s newly introduced BioFlow 20 bio-remediating aqueous parts washer uses a patented Nature’s Way Parts Cleaning solution which is added to the circulating aqueous fluid. The parts cleaning fluid contains emulsifiers and surfactants to remove grease and other hydrocarbons from the parts, reducing them to tiny colloids.
The hydrocarbons flow down into the reservoir, or bio-chamber under the sink that contains an aerator to provide additional oxygen to the system. "That’s when the naturally occurring, aerobic, nonpathogenic microbes in the solution quickly degrade the hydrocarbons into carbon dioxide, water and other harmless by-products," Myers said. "The microbes actually use the hydrocarbons as an energy source for cell building and reproductive purposes."
Although the microbes used in this system for the most part are used to keep the cleaning solution oil free, there are some products designed to eat the oil from the parts themselves. PHase III, Inc., Mesa, AZ, a manufacturer of environmentally safe microbial products designed to reduce hazardous waste costs in automotive rebuilding shops, offers such a solution.
Darryl Goodchild, executive vice president of sales for PHase III, Inc., explained his product, Eliminator®, a concentrated liquid cleaner/degreaser that includes living microbes – 1.6 billion microbes per gallon of solution to be exact – is designed to be used in equipment from sink and drum parts washers to large spraywashers as a replacement for solvents.
"Eliminator® mixes with water and literally eats oil and petroleum based products from parts, turning them into safer, benign components for disposal," Goodchild said.
Charles Sheffield, CEO for Alabaster Corp., Pasadena, TX, said his oil-eating microbe products for controlling used oil and grease in the shop are blended in a nontoxic, environmentally friendly liquid state. "We also furnish nutrients so those microbes may live and digest petroleum products into harmless waste," he said. "Our products have a shelf life of about one year on the microbes. After adding contamination, there is a 21- to 35-day life span on the microbes."
Sheffield explained microbes and bacteria are single-cell organisms, which live by use of their enzymes. "They are able to break down certain contaminates so that they can contact and utilize carbon as an energy source," said Sheffield.
Sheffield said although some microbes digest oil, the most proficient microbes cannot live in petroleum products. "These microbes live in water, which allows them an oxygen support system as an aerobic digestive mechanism," Sheffield explained. "The digestive consumption rate can be tens or hundred times faster than nonaerobic consumption. However, since the petroleum products are not soluble in water, this limits the microbes somewhat."
Sheffield said common automotive fluids such as gasoline, diesel fuel, automotive oils, transmission fluid, power steering fluid and automotive grease can all be digested by microbes. "However, each of these products can require a different microbe blend," Sheffield explained. "Alabaster has 86 different microbes that can be blended together for the use of decontamination."
Besides the liquid variety available from Steelabrator, Alabastor and PHase III, oil-eating microbes are available in various other forms. Some microbes are freeze-dried along with other nutrients and are added to aqueous parts cleaning equipment in a powder form. When added to the solution, the microbes immediately activate and begin the oil digesting process.
Microbes can also be impregnated into a specially designed filter mat in parts cleaning equipment such as units available from Graymills. "During the parts cleaning process, living microbes which are stored in the replaceable BioFilter, are released into the solution," said Graymills’ McCollom. "These safe, hydrocarbon-converting microbes actually cleanse the liquid of organic impurities."
As the cleaning solution containing hydrocarbons continuously flows through the filter of the parts cleaning equipment’s closed-loop unit, the microbes digest the oils that become trapped in the filter’s fibers.
PHase III also offers shops Oil Sponge®, a remedial absorbent made of reclaimed cotton fibers with an oil-eating microbial culture (1.6 billion per 30 lb. bag). Like clay absorbents, the powdered Oil Sponge absorbent is spread over spilled oil, fuel, grease and other automotive liquids on the shop floor. But unlike clay, after absorbing the oils, the microbe-based powder is swept up and can be disposed of outdoors on a compost heap where the microbes continue to digest the oil.
Another microbe formulation that is of interest to machine shops are Bio-Disks available from RGF Environmental Systems, Inc., West Palm Beach, FL. Containing a live synergistic blend of Class I bacteria specifically chosen for its accelerated ability to metabolize gasoline, oil and other fuels, Bio-Disks are designed to be added to cleaning equipment oil-water separators and holding pits.
According to RGF, used alone, the Bio-Disks can reduce petroleum hydrocarbons from an oil-water separator by up to 50%. When used with an aerator system, Bio-Disks’ microbes digest about 80% of the hazardous materials, thus reducing a shop’s waste removal costs.
Although not all bio-remediation parts cleaning equipment contains bio-filters, they do have some type of filter which is designed to trap inorganic sediments, metals, dirt, rubber and other suspended solids that are not digested by microbes.
Myers said, by design, bio-remediation systems will provide savings in addition to waste removal and treatment costs. Because these systems are self-cleaning through the biological conversion of oils and greases, cleaning solutions do not become spent and have to be replaced or disposed of.
"Cleaning solution is added only to replace small amounts of liquid lost through evaporation or that which is left on the part," Myers said. "The only disposal is the filter that is saturated with particulate matter. The filters are designed to last about three months and are disposed of in accordance with your local and state regulations." Other manufacturers offer reusable filters which can provide additional costs savings.
One of the improvements in bio-remediation technologies includes bio-stimulation, which involves adding nutrients or oxygen to augment the actions of microbes already present in parts cleaning equipment. Steelabrator’s Myers said in the early developmental stages of bio-remediation, oil-eating microbes were not provided oxygen, and they would die off, and allow for anaerobic microbes to take over. Unfortunately, the anaerobic microbes would leave an unpleasant sulfur odor as they digested oil and grease. Most people were turned off by such equipment. But today, Myers said parts cleaning equipment has evolved to operate with aerobic microbes, which need oxygen to survive. Additional oxygen is supplied to aerobic microbes with an aerator.
And most bio-remediation cleaning systems use heating elements to not only enhance the cleaning solution performance, but to keep the microbes alive longer. "The systems we have today operate at temperatures around 100° F, which prolongs the life of the microbes, and is comfortable for the operator of the cleaning equipment," Myers said. "Bio-remediation products are also an answer to worker safety by eliminating caustic and irritating cleaners."
The bio-remediation market
According to FIND/SVP, a New York, NY, research and consulting company, the use of bio-remediation has grown steadily in recent years as an answer to pollution and hazardous waste reduction.
FIND/SVP reported bio-remediation in 1995 was a $228 million market within the much larger U.S. hazardous waste remediation market. The market has grown rapidly since it first emerged as a commercial-scale technology in the mid-1980s. FIND/SVP predicts by the year 2000, the bio-remediation market will more than double to about $475 million per year. The U.S. bio-remediation market is made up of consulting, contracting and laboratory services; microbe and nutrient production; and equipment such as bio-reactors and bio-filters.
FIND/SVP reports that of these sub-markets, consulting, site assessment and remediation services make up the greatest portion (89% in 1995), while product and equipment sales make up the remaining 11%.
When faced with the advantages bio-remediation offers, such as hazardous waste reduction and cost savings, it’s easy to see why this process is expected to grow.