Materials Used to Remove Oil From Seawater

Oil has become an indispensable part of modern life, providing us with such everyday essentials as the gas for the cars we drive and fabric for the clothes we wear (even polyester is a petrochemical material). However, as the demand for petroleum-related products rises, so does deep sea drilling, crude oil sea-borne transportation and other activities that can and do sometimes result in oil spills. Fortunately, people have invented ways to limit the damage made by such spills to human health and the environment; and substances that help remove oil from sea water are among the chief oil spill response techniques.

Dispersing Agents

• The first line of defense against oil spills is dispersing agents or dispersants--chemicals that help break crude oil into small droplets that are then broken down naturally by sea waves and currents. Because light and medium weight oils disperse much better than heavy crude oils, oil cleanup teams apply dispersing agents during the first stages of the cleanup efforts, before the light materials in the spilled oil have evaporated.

Gelling Agents

• Gelling agents, or solidifiers, are chemicals that transform oil into rubberlike solids that the cleanup teams can then much more easily remove from the water using nets and skimmers (a skimmer is a device used for collecting spilled oil from the water's surface). However, because you need as much as three gallons of the gelling agents to solidify one gallon of oil, this material is largely impractical for large spills where millions of gallons of oil need to be removed from the water.

Biological Agents

• Biological agents are widely used to remove oil from sea water. Biological agents are organisms or chemicals that increase the rate of natural biodegradation, a process that "recycles" the oil in a natural fashion with the help of microorganisms such as bacteria, yeast and fungi. If left alone, oil degrades very slowly, often in a matter of years, and until it is fully decomposed, it can damage the delicate marine ecosystems. Biological agents help biodegradation processes go faster. The primary cleanup techniques that employ biological agents are fertilization--providing the microorganisms capable of biodegradation with the nutrients to make them grow faster (e.g., phosphorus and nitrogen)--and seeding--adding such microorganisms to the contaminated environment.