Beyond the Molecular Frontier Challenges for Chemistry and Chemical Engineering (2003) / Chapter Skim
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9 Atmospheric and Environmental Chemistry
9 Atmospheric and Environmental Chemistry
Pages 148-159
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From page 148... ...
9 Atmospheric and Environmental Chemistry iAs part of the overall project on Challenges for the Chemical Sciences in the 21st Century, a workshop on The Environment will lead to a separate report. The reader is urged to consult that report for further information.
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From page 149... ...
Systems in place ranging from laws and policies of government regulatory bodies to voluntary programs of the industry are intended to anticipate, detect, and prevent unacceptable risks to the public, both now and in the future. The ability of chemists and chemical engineers to meet these challenges, as contributors to and beneficiaries of the chemical enterprise, requires that they utilize the best science available today and aggressively advance that science in the future.
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From page 150... ...
gases such as chlorofluorocarbon refrigerants cause degradation and depletion of the ozone layer. The ozone layer plays an important protective role for life on earth by blocking very-high-energy ultraviolet light; consequently, this fundamental atmospheric chemistry has important practical consequences.
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From page 151... ...
For example, burning petroleum components in gasoline and diesel engines of vehicles can lead to air pollution by emission of unburned hydrocarbons and sulfur and nitrogen oxides produced during the combustion process. When this was realized, fuels were refined differently to reduce sulfur content and vehicles were fitted with catalytic converters, designed by chemists and chemical engineers, to remove the hydrocarbons and nitrogen oxides from vehicle exhaust.
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From page 152... ...
When they reach the stratosphere where the ozone layer is found the greater intensity of high-energy radiation from the sun finally causes slow decomposition of the CFCs. This decomposition process produces chlorine atoms that catalyze the destruction of ozone in a chemical sequence that is now well understood.
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From page 154... ...
Microbes in the soil are capable of converting organic chemicals to other compounds, and in the ideal case to CO2 and H2O, and some microbes have been found to convert heavy metals to complexes with reduced toxicity. Microbes can be harnessed through addition of nutrients, other chemicals, or specific microbes to enhance beneficial microbially mediated chemical reactions.
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From page 155... ...
No longer do industrial plants belch foul smoke into the atmosphere, and no longer do chemical plants discharge brown or orange sludge into nearby streams and rivers. These improvements have been implemented by chemists and chemical engineers, and they have been implemented in ways that often have provided economic benefits to the United States.
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From page 156... ...
156 BEYOND THE MOLECULAR FRONTIER activity continues to destroy forests, will this affect the carbon dioxide cycle and levels, and what can be done about that?
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From page 157... ...
The world's food supply will depend on the discovery of new insecticides that do not harm unintended targets in any way and other agricultural chemicals such as herbicides and fertilizers that are neither harmful nor overly persistent. Other sectors of the chemical industry will rely on the invention of new and selective catalysts that enable the manufacture of useful products, including polymers, without producing unwanted waste products and without using excessive energy.
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From page 158... ...
When we burn coal, not only do we produce carbon dioxide, the major product, but we can liberate small amounts of mercury and larger amounts of sulfur dioxide. The mercury can form toxins that harm fish as well as humans, while sulfur dioxide can produce acid rain that destroys forests and water supplies.
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From page 159... ...
If we are to provide a favorable legacy for future generations, chemists and chemical engineers will need to develop effective ways to clean up existing waste and find ways to prevent the generation of waste in the future. And most importantly, they will need to develop a system that is fully sustainable that will safely provide the energy, chemicals, materials, and manufactured products needed by society while neither irreversibly depleting the earth's scarce raw materials nor contaminating the earth with unhealthy by-products.
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