Friday 17 May 2013

4.15 understand the biological consequences of pollution of water by sewage, including increases in the number of micro-organisms causing depletion of oxygen

Sewage contains nutrient which enable algae to flourish. They take up sunlight and oxygen. Many fish die and other organisms die. Decomposers thrive on there dead bodies; meaning even more oxygen is taken up by microorganisms.

Basically its the same process as eutrophication.

3 comments:

  1. Because they block out the sunlight

    ReplyDelete
  2. The Biology Syllabus has changed…

    Here is a New blog for the 2017 Syllabus:

    http://igcse-biology-2017.blogspot.hk

    ReplyDelete
  3. more at

    http://igcse-biology-notes.blogspot.hk/2017/06/415-understand-biological-consequences.html

    ReplyDelete