• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Atmospheric Pollution Caused By Coal-fired Power Stations And Motor Vehicle Engines.

Extracts from this document...


Atmospheric Pollution Caused By Coal-fired Power Stations And Motor Vehicle Engines Photochemical smog contains a mixture of primary and secondary pollutants. Primary pollutants are released directly into the atmosphere whereas secondary pollutants undergo further reactions (1). The main primary and secondary pollutants in the atmosphere are shown in table 1 below. Table 1 Primary Pollutants NOx (NO + NO2), VOCs, CO Secondary Pollutants O3, NO2, H2O2, PAN, Partially oxidised VOCs, HNO3 The two main types of primary pollutants are oxides of nitrogen and VOC's (Volatile organic compounds) mostly hydrocarbons. Both are naturally present in the atmosphere but human activity heavily adds to this. Oxides of nitrogen are always produced when fossils fuels are burnt at a high temperature e.g. in a motor vehicle internal combustion engine. 95% of this is NO, which is a primary pollutant, with only small amounts being NO2 which is a secondary pollutant. Unburnt fuel in motor vehicles also releases hydrocarbons into the atmosphere. ...read more.


The Null Cycle With No Hydrocarbons Present More hydrocarbons in the atmosphere will mean more NO2 will be available to produce more oxygen atoms and therefore more ozone. The following two reactions show the first two steps of breaking a hydrocarbon Reaction 4: RCH3 + OH ==> RCH2 + H2O Reaction 5: RCH2 + O2 ==> RCH2O2 The peroxy radical RCH2O2 then reacts with NO to form NO2 (5): Reaction 6: RCH2O2 + NO ==> RCH2O + NO2 These reactions provide a means of regenerating NO2 from NO which does not involve the destruction of ozone so the concentration of ozone rises. At Longannet, SOx emissions are reduced by a process called 'sea water scrubbing.' This involves passing the fuel gasses through the seawater allowing the SOx to dissolve producing sulphite ions in the water. The seawater is aerated (air is passed through the seawater) to oxidise the sulphite ions to sulphate ions, which are more suitable for disposal at sea. ...read more.


This is why the 'Gas Reburn,' system being used as the BPEO for reducing NOx emissions at Longannet. Chemists have used various techniques to research the formation of photochemical smog. These include the monitoring of tropospheric pollutants. This provides data for the concentrations of pollutants involved in the production photochemical smog, at different times in the day. Chemists can then use this data to deduce when photochemical smog is most likely to occur. By studying individual reactions in the laboratory, which are known to be involved with production photochemical smog, chemists can begin to make predictions about rates of reactions. The findings and predictions can be fed into a computer to produce an accurate computer model that can be used for simulating different scenarios/situations. Finally tests can be carried out on a grand scale in smog chamber simulations. All these techniques are very important as emissions of primary pollutants increase worldwide every year so any decisions made are based on firm scientific understanding of the processes involved. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Environmental Management section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Environmental Management essays

  1. TOPIC: OZONE - DEVIL IN DISGUISE?1.0 INTRODUCTION Ozone (O3) is an allotropic ...

    Ozone then becomes a secondary pollutant in the formation of photochemical smog, a complex form of air pollution. Ozone can further react with hydrocarbons to form other secondary pollutants such as aldehydes, ketones and peroxyacyl nitrates, all of which are strong oxidants that irritate the eyes and throat.

  2. I am going to research waste pollution. I have chosen to research waste pollution ...

    new research showing that there are much better ways than incineration to treat residential waste. Useful measures would have included removing the �50 million worth of subsides given to incineration or the introduction of an incineration tax. Mike Childs, senator waste campaigner at friends of the earth, said: 'Communities across

  1. Pollution levels - Record the pollution level of a particular pollutant in five different ...

    Health Effects SO2 ==> Fall in lung function for asthmatics ==> Tightness in the chest ==> Coughing Particles PM10 ==> Cause inflammation to people of heart and lung diseases. ==> May carry surface-absorbed carcinogenic compounds into the lungs Carbon Monoxide (CO)

  2. Ozone (O3) is an allotropic form of oxygen with three atoms in each molecule. ...

    CFCs are non-toxic, unreactive, non-flammable and cheap to produce. They are used as refrigerants, cleaning solvents, blowing agents for plastics and aerosol propellants. As stable molecules, they can last up to 75 years in the atmosphere, during which they are blown to the stratosphere.

  1. Sociocultural Factors Affecting BP Petrol Filling Stations in the UK

    0.85lb. Renewable Hydrogen Cell 0.25lb. 0.00lb Source: bullnet.co.uk This table shows just how much better for the environment a fuel cell engine is, and Mercedes have developed one. The only stumbling block is the �300,000 price tag, which is a lot compared to the petrol engine A-Class at nearer �15,000.

  2. Photochemical smog.

    with limestone which will form calcium sulphate (CaSO4).This is called the limestone process. Another option is to dissolve sulphur dioxide into seawater. There are two methods for lowering NOx emissions as well. * Outline the part played by chemists in the research on photochemical smog formation.

  1. In urban areas like London motor vehicles, amongst other sources, are the main cause ...

    The changes in both of the these gases increasingly cause the combustion process to change from one of complete combustion to one of incomplete combustion, resulting in the production of increasing amounts of CO. Adapted from http://www.bartleby.com/65/ai/airpollu.html Photochemical smog is a result of photochemical reaction involving primary pollutants.

  2. Air pollution - Accurate identification of activities and legislation which reduce the harmful effects.

    Legislation to control smoking is in effect in some locations, but personal exposure should be monitored and limited wherever possible. There are many places now which have band smoking in public places. When it comes to the environment, even the smallest individual action really does make a difference - and can benefit you too!

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work