topic 7

• biomass is the mass of living material
• rate of decay affected by water, temperature, decay organisms and oxygen
• biogas cannot be stored as a liquid and needs to be used straight away
• batch generator

  1. makes biogas in small batches
  2. manually loaded with waste and then digested
  3. by products cleared away after end of every session
• continuous generators

  1. makes biogas all the time
  2. waste continuously fed and gas is produced at a steady rate
• pollution affects air as it as it release smoke and acidic gases into the atmosphere
• pollution affects water as sewage and toxic chemicals can be released into lakes and river
• consequences of global warming include

  1. rising sea levels - seawater expands and ice melts
  2. changes in species distribution
  3. changes in migration patterns
  4. reduced biodiversity