Q9
(a) Briefly describe the environmental impact of NOx and SOx and allowable limitations as per Annex VI of MARPOL in emission control areas and outside emission control areas.
(8)
(b) Briefly describe methods to control NOx emission
(4)
Reference Answer
### Part (a): Environmental Impact and MARPOL Annex VI Limitations #### Environmental Impact of NOx (Oxides of Nitrogen) NOx is a family of poisonous, highly reactive gases formed when fuel is burned at high temperatures. In marine diesel engines, this primarily occurs through the reaction of atmospheric nitrogen and oxygen in the combustion chamber. * **Acid Rain:** NOx reacts with water, oxygen, and other chemicals in the atmosphere to form nitric acid (HNO₃). This falls to the earth as acid rain, which damages forests, acidifies lakes and streams (harming aquatic life), and corrodes buildings and materials.
Full answer on MeoMock — surveyor-grade reference answers for 7,000+ written exam questions.