TECHNOLOGY
Microorganisms consume oil in test spills Oil-degrading mixture of microbes, nitrogen, and phosphorus cleans test beds in four days A method of cleaning up oil spills by accelerated microbial biodegradation— in effect "eating up the 011"—is being developed by Dr. Edward N. Azarowicz of Bioteknika International, Inc., Alexandria, Va. Progress on development of the new oil cleanup technique was revealed to C&EN in a field demonstration and an interview with Dr. Azarowicz and Byron A. Moe, president of the small, nine-month-old pollution control company. Called Petrodeg, the petroleum-degrading agent contains a mixture of 20 microorganisms—one of marine origin and the rest terrestrial organisms. The agent also contains necessary chemical nutrients for microbial growth, particularly nitrogen and phosphorus compounds.
Petrodeg microorganisms enter oil drop and feed inside (500 X magnification)
The microbiological species in the mixture were selected by Dr. Azarowicz for their capacity to metabolize oil hydrocarbons rapidly and completely. The Virginia microbiologist says that laboratory and field tests in salt water and brackish river estuaries—at water temperatures between 55° and 84° F.—show that Petrodeg completely cleans up every kind of oil tried in as little as four days. Ultimate fate. Development of the Petrodeg method comes amid intensi48 C&EN SEPT. 7, 1970
fying research on oil biodegradation. Relatively little is yet known on the ultimate fate of oil in the oceans—after visible oil slicks have disappeared. One of the still most widely used methods of combating oil spills is dispersing the slick with chemical dispersants. This method is based on the supposition that dispersal into small oil droplets with large surface area will, on the one hand, eliminate harmful effects of masses of oil, and on the other hand facilitate natural hydrocarbon biodegradation processes carried out by marine microorganisms. However, the known toxicity of many chemical dispersants to shellfish is an inhibiting factor, and federal limits have already been set on their use (C&EN, July 27, page 34). Furthermore, as indicated in recent testimony before Congressional committees, oil droplets dispersed from an oil slick may end up as toxic hydrocarbons in edible fish and shellfish tissue. Dr. Max Blumer of Woods Hole Oceanographic Institution in Massachusetts has carried out probably the first major study, using sophisticated analytical methods, of the long-term chemical and biological effects of an ocean oil spill. He concludes that natural microbial oil degradation in the ocean is very slow. Although oil is no longer evident visually from a September 1969 spill in West Falmouth, Mass., Dr. Blumer's chemical analysis reveals oil's persistent presence in bottom sediments and in shellfish. Under natural conditions, straightchain hydrocarbons are degraded faster than branched chains, and aromatics—potential human carcinogensare degraded slowest of all, he adds. Enriched cultures. The idea has therefore occurred to a number of scientists of accelerating natural microbial biodegradation of oil in oceans by spraying oil slicks with enriched "oileating" cultures. Dr. Blumer tells C&EN that he sees as a key to oil cleanup the finding of microorganisms preferentially attacking aromatics. Studies are proceeding at several laboratories to develop such enriched cultures for "seeding" oil spills. For example, Dr. Carl H. Oppenheimer,
Russell J. Miget, and Howard I. Kator, department of oceanography, Florida State University, Tallahassee, are investigating the oxidation and degradation of crude oil fractions by naturally occurring marine microorganisms. They are using organisms isolated from sites exposed to long-term oil seepage or pollution (and presumably most adapted to oil degradation). They will identify degradation products and rates, particularly of aromatics, and determine product toxicity. Another investigation aimed toward eventually seeding oil spills with oildegrading bacteria is being carried on by Dr. Richard Bartha, Rutgers University, New Brunswick, N.J. Dr. Bartha has isolated oil-degrading marine microorganisms, and is studying degradation rates, intermediates, and products. Both Dr. Bartha and Dr. Oppenheimer plan field tests within the next year. Practical use. The Bioteknika method, Petrodeg, may be closer to practical use than other biodegradative methods. Mr. Moe hopes to hold a test for Coast Guard observers this month. And he plans startup, before the end of the year, of a pilot plant including 60-gallon fermentors. In field tests until now, Dr. Azarowicz has used straw soaked in Petrodeg for application to oil test beds.
Oil spill control R&D efforts encompass a variety of approaches Attempts to achieve accelerated biodegradation of petroleum are only one facet of an important and growing research and development effort to upgrade oil spill control technology. Although some oil spill research was carried on previously, serious efforts began mainly after the huge Torrey Canyon spill off England in March 1967. An impetus to U.S. efforts was the Santa Barbara spill in early 1969. The largest effort, the federal oil pollution control R&D program, is coordinated by a task group of the National Interagency Committee for Control of Pollution by Oil and Hazardous Materials, with representatives from many agencies active in the field. However, according to Ralph Rhodes, chief, marine pollution control section, Federal Water Quality Administration (FWQA), about 9 0 % of the federal programs are carried on by the Coast Guard and FWQA.
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Dr. E. Azarowicz (left), and Ron Withers pour oil into test bed and add straw coated with Petrodeg oil-degrading organisms
However, construction of special pelletizing machinery will allow production of pellets of lyophilized dry material for storage and for more effective application by spraying. A number of questions still remain to be answered about practical application of the Petrodeg method. Dr. Azarowicz believes that his microorganisms produce no toxic products, but break the oil down to carbon dioxide and water and form a cell biomass. Preliminary tests are under
FWQA's budget for oil spill R&D in fiscal 1970 was $2 million. Another $2 million has been approved for 1971 and a request has been submitted for additional funds. The Coast Guard—according to Cmdr. Daniel B. Charter, Jr., chief of the Pollution Control Branch, Office of Law Enforcement—had a budget in fiscal 1968 of close to zero for oil spill R&D. In fiscal 1969, about $1 million was spent, and in fiscal 1970 this increased to $4 million. Budget for fiscal 1971 is again about $4 million, but the Coast Guard hopes to obtain appreciably more for 1972. Growth. For a fuller picture of growth in the Coast Guard's activities, however, Cmdr. Charter cites figures for its total maritime environmental protection program, including not only R&D but also acquisition of systems, construction, and operating expenses. This budget was $6.5 million in fiscal 1970, is expected to be $21 million in fiscal 1971, and may rise to $34 million in fiscal 1972. One Coast Guard program, to be tested this fall, is aerial surveillance of offshore waters by aircraft bearing sensors to detect illicit oi! discharges and to follow movement of known
way to ensure nontoxicity of degradation products. Another question is whether a method that works in the laboratory and in protected test beds will also work on massive oil spills in the heavy waves and cold temperatures of open seas. Dr. Azarowicz has found under the microscope that his microorganisms not only operate at the oil-water interface of oil droplets, but apparently also enter into the droplets. He believes that waves and heavy seas would
spills. The Coast Guard hopes to start full-scale monitoring by 1974. Mechanical devices. The main focus of both FWQA and Coast Guard oil spill programs is on mechanical containment and collecting devices, although other methods are also being studied. The Coast Guard has already successfully tested in prototype its air-deliverable antipollution transfer system (ADAPTS), involving transfer of oil from a stricken tanker to large rubber bladders (C&EN, May 25, page 15).. It plans rough-water tests on the system before deciding about acquisition. Another Coast Guard program is development of "signature techniques" for determining origin of oil in oil spills, to establish legal responsibility for spills of unknown origin. An FWQA-sponsored study is looking at tracer techniques, with the idea of perhaps putting an inert chemical tag into each tanker load—with a "fingerprint" specific to a ship or company. Also sponsored by FWQA are the studies of Dr. Max Blumer, Woods Hole Oceanographic Institution, and Dr. Carl Oppenheimer, Florida State University, on biodegradation of oil. Tests for effectiveness and toxicity of
only increase aeration and mixing, actually promoting microbial growth, and microorganisms would stick to or stay inside moving oil droplets. In any case, it seems that the first potential application of Petrodeg might be for use in enclosed waters— for example, small spills in harbors— or to clean ship bilge water and tank sludge of oil tankers. In the present undeveloped state of oil cleanup technology, this could by itself be a step forward.
chemical dispersants are being developed (C&EN, August 24, page 31). Oil industry. The American Petroleum Institute (API) has an active program in oil spill control R&D. Starting after the Santa Barbara spill in early 1969, API will spend $1.3 million by the end of 1970 on its outside contracts, according to Dr. Jack R. Gould. API anticipates a similar 1971 budget. Individual oil companies are also active in oil spill control work. For example, biodegrading bacteria for tertiary treatment of refinery effluent—removing final traces of o i l — are being studied at Texaco's research lab in Richmond, Va. Long-range toxicological studies on chemical dispersants are going on at Standard Oil (NJ.).. Mobil Oil Corp. and Adec, Inc., have developed a very sensitive system for detection of oil pipeline leaks, to be installed in September in Santa Barbara offshore pipelines. Shell Oil Co., one of the more active companies in oil spill control, spent about $750,000 in oil spill R&D from July 1969 to June 1970. Much of the research, on containment and collection devices, is concentrated at Shell Pipe Line Corp.'s lab in Houston, Tex.
SEPT. 7, 1970 C&EN 49
