The problem with organic waste
In I/GCSE Biology exam, don't forget to remember what organic waste is!
In UK - over 7.6 million tonnes of food wasted !!!!!!
- Do you remember what decay is in I/GCSE Biology?
- Food + drink wastes ➡️ organic – originally come from plants / animals
- Waste decay as bacteria, fungi grow on them
- Most UK waste disposed in landfill sites
- once organic waste buried, decay organisms can’t grow
- not enough oxygen for aerobic respiration
- Decay method
- methanogens can grow anaerobically
- release methane (flammable + global warming)
- Meat waste attractive to pests e.g. rats, councils ask to separate waste e.g. cans, glass, food etc.
Landfill tips vented in a controlled way for many years after tipping has ended, otherwise methane that forms as the refuse decays might explode or create fires that burn below the surface for weeks.
A selection of choices
Manage garden + vegetable kitchen waste
- ➡️ compost heap – waste piled up and microbial decay breaks it down into compost
Councils collect this as green waste
- make compost in large scale, process called windrow composting
- needs space + compost material turned regularly (keep oxygen level hug) no special equipment needed
- Windrow composting - outdoor composting on a large scale
Other councils collect garden + kitchen waste together
- composting in large containers until meat waste is broken down, process called In-vessel composting
- In-vessel composting – forming compost from waste plant material within a large vessel in which conditions of temperature and moisture can be controlled
- Composting complete by using windrow process
- conditions monitored inside containers + correct moisture + temperature maintained
- The high temperatures kill pathogens + seeds of weed plants
- Other process ➡️ anaerobic digestion ➡️ the breakdown of dead plant and animal material without oxygen
- Food waste put into large digesters + air is excluded
- Methanogens break down material + release methane – methane collected, used to produce heat – process can’t use wood waste because microorganisms can’t break it down
- In all processes, the solid end materials can be used for soil conditioning (gardens, parks etc.)
- "The Gifts from Organic Waste", https://static.wixstatic.com/media/0b6b65_c2ab17fc0e2d46a2a83e41d81979db4f~mv2.jpg/v1/fill/w_749,h_562,al_c,q_90/0b6b65_c2ab17fc0e2d46a2a83e41d81979db4f~mv2.jpg
- "Windrow Composting", https://4.imimg.com/data4/KU/TE/GLADMIN-30459837/d1-500x500.jpg
- "Pin på Novel", https://i.pinimg.com/originals/cd/65/15/cd6515daaa09ceeb69fa50ceb064133d.jpg
And we're done with this topic! Well Done!
Drafted by Alyssa (Biology)