Gentlemen: I thought that the following
theoretical article might be of interest relating to the present oil spill in the Malacca
Straits. I wrote this while in Kuala Lumpur at the 1993 Oil Spill Conference
where I was invited to present a detailed talk on biormediation of oil spills. As an
oceanographer I was interested in the mechanics of an oil spill.
This is a synopsis of a hypothetical oil spill and potential historical response protocol
using bioremediation with a enriched microbe powder, a special and unique mixture of
natural concentrated hydrocarbon oxidizing microorganisms, specifically selected to remain
at the oil water interface.
It was 3:30 AM on a dark and stormy night in the north Malacca Straits when two ships
collided. One was a bulk crude oil carrier of 55,000 tons, the other a coastal freighter.
The crude oil was a medium density of API 25. The smaller coastal freighter had no running
lights and apparently the watch knew the local waters and was slowly moving away from the
Malaysian coast. The tanker proceeding south at 18 knots struck the bow of the freighter.
The collision struck the front port side of the tanker below the water line and then
scraped along the side of the oil carrier ripping a wide scar along the port side.
The collision occurred approximately 20 miles off the Malaysian coast above Penang Island.
A light wind of 5 knots was blowing from the north west.
Oil started to pour out of the side of the tanker. About 40 percent of the tanker
compartments were within the damaged area with a potential of releasing approximately
20,000 tons of the medium heavy crude oil from the China Sea. The wind started to move the
oil toward the Malaysian coast and the beautiful beaches of north Penang. The wind started
the physical spreading and evaporation, and the waves started to break the oil into
streaks and patches. The wave action was not enough to physically emulsify the oil.
The nearest booms and skimmers were many hours away. Detergents were closer in time but
these could do damage to the sensitive Malaysian coastal beaches, rocky coast and Mangrove
flats. Any traditional response would take hours if not days.
The only obvious immediate treatment was the new response technique, bioremediation with
applied microorganisms. The ship owner had previously stockpiled for such an emergency, a
cubic meter (1 1/2 tons) of enriched microbe powder with a density of 1011 cells per gram.
The crew immediately started to spread the microbial powder by hand as the oil poured from
the boat side. The application rate was approximately one half kilo per cubic meter of
oil. The productive coastal waters had appropriate amounts of inorganic nutrients for
adequate hydrocarbon degradation.
To initiate the skimmer and absorbent response program, time was being consumed to
organize all the responsible committee members and the skimmers, detergents and booms.
During this time delay the microbial seeding from the ship was already working.
What happened as an immediate bioresponse? The oil released from the ship was continually
inoculated with oil degrading microorganisms. These microorganisms were designed not only
to grow rapidly on the oil but to produce foam as a result of the production of fatty acid
detergent agents from the oil and to remain in the oil as it spread over the water
surface. While the oil was spreading, the microorganisms were using the oil to multiply
and increase the biological activity relative to time of spreading. The resulting natural
detergent action produced a mousse that increased the water oil interface and the
biological activity, as the slick moved from the source.
As the oil moved toward the coast of Malaysia it was continually being converted to fatty
acids by microbial oxidative biological activity that is directly related to microbial
biomass, and time. The biological activity and fatty acids would normally produce an
emulsion even in calm seas. As a result the oil that did hit the beach and rocks and
mangrove flats would not have the usual physical oil properties and biological degradation
would continue on the shore area.
The alternate response, as identified by the current oil spill contingency programs, is
quite different. It would take hours or days for the normal response of booms, skimmers,
or detergents to be deployed. Meanwhile, the oil would move towards the coast with no
control. When the normal response vehicles were in place, the skimmers, by historical
accounts, could only pick up 20 to 40 percent of the remaining oil. The application of
detergents could affect the physical conditions of the oil but would require one bbl of
detergent for 5 to 10 bbl's of oil and the residual negative effects on the environment
are difficult to predict. The fresh oil reaching the shore would attach to the sand and
rocks and evaporate to produce a varnish-like black coating.
The value of bioremediation, with properly designed microbes, is based on their ability to
respond to any water or environmental condition, rough open sea and any wave action, or in
the quiet waters of a mangrove swamp or coastal beach. The organisms naturally work in the
water at the oil interface, and, as the sea becomes rough and the microbes continue to be
active. An emulsion will be produced from the action of the fatty acids resulting as the
by product of natural surface populations including phyto and zooplankton.
The combined natural response and induced bioremediation change the physical properties of
the oil. The oil is altered by the colloidal chemistry of the surface film. The result is
a colloidal emulsion of oil in water that does not physically respond to solid surfaces as
an oil. When it reaches the coastal rocks, mangroves or sands, the emulsion does not
produce the varnish or coating normally associated with the weathering of fresh oils on
solid surfaces.
Instead of forming the usual oil coating that makes the coastal areas oil destructive, the
oil is changed by the biological activities to produce an oil emulsion related to the
physical properties of the oil and the surfactants produced by the microorganisms. The
resulting oil emulsion does not adhere tightly and biological degradation continues as the
oil environmental conditions are favorable.
Bioremediation is based upon the enhancement of a natural environmental balance system in
which the oil impacted environment is directly treated with an inoculum of a million
active mixed microbial cells per gram or cubic centimeter of pollutant, and designed to
stay within the polluted areas, to degrade hydrocarbons to fatty acids and ultimately to
carbon dioxide and water through the total activities of the food chain.
All present contingency plans have a maximum efficiency in the open sea of less than 40
percent recovery and are normally much less as the sea becomes rougher. Bioremediation
does not interfere with physical response and therefore can increase the overall recovery
or removal. However, it may also be used alone.
Bioremediation is only a process that accelerates the natural cycles of nature. All living
systems and their chemical components must be recycled. Microorganisms have this nature
role.
Hydrocarbon microbiology has a 70-year history with thousands of books and publications.
The activity of microbial hydrocarbon recycling is indisputable.
Copyright 1994
Dr. Carl Oppenheimer
carlo@mail.utexas.edu
