环境科学专业英语7.ppt

1、,Petroleum Pollution,Jinyan Yang,29-11-2010,Translation,1) About half of the oil that contaminates the ocean from natural seepage from offshore deposits. One-fifth comes from well blowouts, breaks in pipelines, and tanker spills.,2) About 25% of the crude oil in a spill is volatile and evaporates wi

2、thin three months. Other compounds, relatively nonvolatile but lighter than water, float on the surface, where they are broken down by bacteria over the next few months.,3) The damage resulting from an oil spill also depends on when it occurs. Had the spill occurred after the migration of ducks and

3、other waterfowl the damage might have been much less.,4) Thanks to public outcry and stricter controls, the number of oil spills began to fall after 1980 and has remained relatively stable in recent years.,5) Dual radar systems, backup steering controls, collision avoidance aids, and improved inspec

4、tion and certification were instrumental in reducing spills.,6) Although the number of oil spills has decreased, the quantity of oil released fluctuates wildly. In 1984, for example, approximately twice as much oil was released as in 1983 in about the same number of spills.,7) Under the bill, oil co

5、mpanies would ultimately be responsible for cleanup costs, but only to a point, because the law sets limits on their financial liability.,Questions,1) What harmful effects do oil spills pose?,2) Does an oil spill float on the ocean surface forever or will have some changes? How will it be?,3) What does the amout of damage caused by oil pollution depend on?,4) What does the crude oil consist of according to its physical property?,5) Should we be feared or not be feared for oil pollution of the oceans? Why?,Preparation for Unit 10 -Municipal Solid