Section outline

  • General

    Collapse all Expand all

  • 减少空气污染

    A hydrogen fuel-cell car being refueled at a hydrogen station.
     

    Can a car run on hydrogen?
    ::汽车能用氢气运行吗?

    Hydrogen fuel-cell cars use hydrogen to charge a battery, and emit only  water vapor  as exhaust. So far, there are only a few models available. A major problem with hydrogen cars is the lack of hydrogen  fuel . Hydrogen fueling stations are not as common as regular gas stations, and the process of refining hydrogen for use in fuel-cell cars is energy-intensive. Still, they are one of many new technologies that could help reduce air pollution in the future.  
    ::氢燃料电池汽车使用氢充电,仅排放水蒸气作为废气。 到目前为止,仅有几种模型可供使用。氢燃料汽车的主要问题是氢燃料的缺乏。氢燃料厂不像普通加油站那样常见,燃料电池汽车使用的氢提炼过程是能源密集型的。 然而,氢燃料电池汽车是许多新技术之一,可以在未来帮助减少空气污染。

    The Clean Air Act
    ::《清洁空气法》

     is a measure of the pollutants in the air. More pollutants mean poorer air quality. Poor air quality started to become a serious problem after the  Industrial Revolution . Factories burned  coal  for  energy .  Gasoline  burned by cars and trucks added greatly to air pollution. By the mid-1900s, air quality in many big cities was very bad. Incidents in London and in U.S. cities alerted people to the extent of the problem. It was clear that air quality needed to be protected.
    ::空气中的污染物是空气中的污染物。 更多的污染物意味着空气质量差。 低空气质量在工业革命后开始成为一个严重问题。 工厂以煤为能源燃烧煤炭。 汽车和卡车燃烧的汽油大大增加了空气污染。 到19世纪中叶,许多大城市的空气质量非常糟糕。 伦敦和美国城市的事件提醒人们注意问题的严重性。 显然空气质量需要保护。

    In 1970 in the U.S., the Clean Air Act was passed. It limits what can be released into the air. The air in the U.S. is much cleaner now than it was 50 years ago. But air pollution has not gone away. Vehicles, factories, and power plants still release more than 150 million tons of pollutants into the air each  year .
    ::1970年,美国通过了《清洁空气法》。它限制了空气中释放的污染物。美国空气现在比50年前清洁得多。 但空气污染并没有消失。 汽车、工厂和发电厂每年仍然向空气中释放超过1.5亿吨污染物。

    Reducing Pollutants from Fossil Fuels
    ::减少来自化石燃料的污染物

    There are two basic types of strategies for reducing pollution from  fossil fuels :
    ::减少矿物燃料污染有两种基本战略:

    1. Use less fossil fuel.
      ::少用化石燃料。
    1. Prevent pollutants from entering the air.
      ::防止污染物进入空气。

    Use Less Fossil Fuel
    ::较少使用化石燃料

    We can reduce our use of fossil fuels in several ways:
    ::我们可以以几种方式减少化石燃料的使用:

    • Conserve  fossil fuels. For example, turning out lights when we aren’t using them saves electricity. Why does this help? A lot of the electricity we use comes from power plants that use fossil fuels, like coal and  natural gas .
      ::保护化石燃料。 比如,当我们不使用化石燃料时,灯光就会熄灭,这样可以省电。 为什么这样有用? 我们使用的许多电力来自使用化石燃料的发电厂,如煤炭和天然气。
    • Use fossil fuels more efficiently. For example, driving a fuel-efficient car lets you go farther on each gallon of gas. This can add up to a big savings in fossil fuel use.
      ::更高效地使用化石燃料。 比如,驾驶节能的汽车可以让您在每加仑的天然气上走得更远。 这加起来可以节省大量化石燃料的使用。
    • Keep up with technology. Hybrid cars use the  heat  from braking to generate electricity, and use gas as a backup fuel.  These produce much less air pollution than regular cars. Electric cars run entirely on battery power and produce no exhaust at all, especially if they can be charged via a renewable energy  source .
      ::紧跟技术。 混合型汽车用制动热来发电,用天然气作为备用燃料。 这些汽车比普通汽车少得多产生空气污染。 电动汽车完全靠电池发电,完全不产生排气,特别是如果它们可以通过可再生能源充电的话。

    Keep Air Free of Pollutants
    ::保持空气无污染物

    Some of the pollutants from fossil fuels can be filtered out of exhaust before it is released into the air ( Figure   ). Other pollutants can be changed to harmless compounds before they are released. Two widely used technologies are scrubbers and  catalytic converters .
    ::矿物燃料中的某些污染物在释放到空气之前可以从废气中过滤出来(图)。其他污染物在释放之前可以转变为无害化合物。两种广泛使用的技术是洗涤器和催化转换器。

    • Scrubbers are used in factories and power plants. They remove  particulates  and waste gases from exhaust before it is released to the air.
      ::工厂和发电厂使用冲洗机,在将微粒和废气排放到空气之前从废气中清除。
    • Catalytic converters are used on motor vehicles. They break down pollutants in exhaust to non-toxic compounds. For example, they change nitrogen  oxides  to harmless nitrogen and oxygen gases.
      ::机动车辆使用催化转换器,它们将排出物中的污染物分解为无毒性化合物,例如,它们将氧化氮改为无害的氮气和氧气。
    Exhaust smoke emerging from a vehicle's tailpipe on a road surface.
     
    Before catalytic converters were required, cars spewed a lot of pollutants into the air.

    Increase Alternative Energy Sources
    ::增加替代能源

    Developing alternative energy sources is important. What are some of the problems facing wider adoption of alternative energy sources?
    ::开发替代能源很重要,哪些问题是更广泛地采用替代能源所面临的一些问题?

    • The technologies are still being developed. This includes sources of alternative energy, like solar and  wind .
      ::这些技术仍在开发中,其中包括太阳能和风能等替代能源。
    • Solar and wind are still expensive relative to fossil fuels. The technology needs to advance so that the price falls.
      ::太阳能和风相对化石燃料而言仍然昂贵。 技术需要进步,以降低价格。
    • Some areas get low amounts of sunlight and are not suited for solar. Others do not have much wind. It is important that regions develop what best suits them. Solar works well in  desert  regions.   works best in wetter areas with large  rivers .  Plains  can often use  . If a   is not well-suited for any of these sources,   is another option.
      ::有些地区日光量低,不适合太阳能,另一些地区没有太多风。重要的是,一些地区要发展最适合它们的风能。 太阳能在沙漠地区运作良好,在大河的湿润地区工作最好。 平原通常可以使用。 如果一个地区不适合其中任何一种来源,那么另一个选择就是它。

    Ways You Can Reduce Air Pollution
    ::减少空气污染的方法

    Everyone can help to reduce air pollution. Just use less  fossil  fuels! How can you do this?
    ::每个人都可以帮助减少空气污染,只要少使用化石燃料! 你怎么能这样做呢?

    • Ride a bike or walk instead of driving.
      ::骑自行车或走路而不是开车
    • Take a bus or carpool.
      ::搭公车或汽车。
    • Buy a fuel efficient car.
      ::购买节能汽车。
    • Turn off lights and appliances when they are not in use.
      ::不使用灯光和电器时关掉灯光和电器。
    • Use energy efficient light bulbs and appliances.
      ::使用节能灯泡和电器。
    • Buy fewer things that are manufactured using fossil fuels.
      ::较少购买使用化石燃料制造的物品。

    All these actions reduce the amount of energy that power plants need to produce.
    ::所有这些行动都减少了发电厂需要生产的能源量。

     

     

     

     

    Summary
    ::摘要

    • Catalytic converters reduce pollution from cars.
      ::催化转换器减少汽车的污染。
    • To reduce air pollution, either use less fossil fuels, or clean emissions before they enter the air.
      ::减少空气污染,减少矿物燃料的使用,或在进入空气之前清除排放。
    • Different types of clean energy can be developed for different locations. Some regions are suited for solar, others for wind, etc.
      ::可以在不同地点开发不同类型的清洁能源,有些区域适合太阳能,另一些区域适合风能等。

    Review
    ::回顾

    1. Why is the Clean Air Act important?
      ::为什么《清洁空气法》很重要?
    1. Why is it important to develop alternative energy sources?
      ::为什么必须开发替代能源?
    1. What can you do to reduce the amount of air pollution you produce?
      ::你能做些什么来减少你造成的空气污染?