Food Waste Recycling
The Big Picture
Almost one third of food produced for human consumption is wasted every year, contributing around 8% of the world’s greenhouse gases. Preventing food waste could save the average household £437 per year, and would have the same C02 emission reduction as taking 1 in 4 cars off the road. Help us prevent and recycle food waste on campus!
What is Anaerobic Digestion and Why is It Important?
Anaerobic digestion (AD) takes food and green waste and breaks it down in airtight digesters. AD is a sustainable process where organic matter, such as food or plant waste, is broken down by micro-organisms called methanogens in the absence of oxygen. This creates biogas (a mixture of methane and carbon dioxide) which we can use as a source of energy. This process also creates a bio-fertiliser by-product. This is rich in nutrients such as nitrogen, potassium, and other elements, and can be used in agriculture or horticulture as liquid fertiliser, or even animal bedding, as part of the circular economy.
1. Reduction of Greenhouse Gas Emissions:
- Landfill: When food waste is sent to landfill, it decomposes anaerobically (without oxygen) and produces methane, a potent greenhouse gas that is significantly more harmful to the atmosphere than carbon dioxide.
- Anaerobic Digestion: AD captures this methane and uses it as a biogas, which can be converted into electricity, heat, or fuel. This not only prevents methane from being released into the atmosphere but also provides a renewable energy source.
2. Energy Production:
- Landfill: Food waste in landfills does not contribute to energy production. In fact, it represents a lost opportunity to recover valuable energy.
- Anaerobic Digestion: The biogas produced during AD can be used to generate electricity or heat, contributing to the renewable energy supply and reducing dependence on fossil fuels.
5. Reduction of Odours and Pollution:
- Landfill: Food waste in landfills can produce unpleasant odours and leachate, a liquid that can contaminate groundwater if not properly managed.
- Anaerobic Digestion: AD systems are designed to manage the decomposition process in a controlled environment, significantly reducing odours and preventing the leaching of pollutants.
6. Economic Benefits:
- Landfill: Sending waste to landfills often incurs high costs, including landfill taxes and fees, especially in regions with limited landfill space.
- Anaerobic Digestion: AD can reduce waste disposal costs and create revenue streams through the sale of energy, biogas, and digestate, making it a more economically sustainable option.
3. Nutrient Recycling:
- Landfill: In landfills, food waste contributes to the accumulation of organic material that is not properly utilised, and the nutrients in the food waste are lost.
- Anaerobic Digestion: After biogas extraction, AD produces a nutrient-rich digestate that can be used as a fertiliser, returning valuable nutrients to the soil and reducing the need for synthetic fertilisers.
4. Waste Management Efficiency:
- Landfill: Landfills are a limited resource, and disposing of food waste in them accelerates the filling of landfill space, leading to a need for more landfills, which have significant environmental and social impacts.
- Anaerobic Digestion: AD is a more efficient use of waste, diverting it from landfills and reducing the overall volume of waste that requires disposal.
Preventable Food Waste vs Non-Edible Food Waste
What is the difference between mouldy bread and a banana peel, and why does the difference matter? There are two main types of food waste: preventable and non-edible. Preventable is once-edible food that should have been consumed but instead is wasted, such as mouldy bread or sour milk. Did you know that the five of the most wasted foods include milk, cheese, potatoes, apples, and bread? Refuse, Rethink and Reduce are three key elements of circular economy which should be applied to our food consumption habits too!
Preventable food waste is the type of food waste that we want to reduce as much as possible - see some tops tips below on how you can easily achieve this.
1. Before You Shop
- Check your fridge, freezer and cupboards to see what you already have and what needs to be used first.
- Make a shopping list and stick to it. This will help you avoid impulse buys and overstocking your kitchen with food that could later go to waste.
- Try writing a meal plan for the week so you only buy what you need - looking ahead can save you time and money.
2. Storing Your Food
- Most foods stay fresher for longer if kept chilled and if you’re not going to eat it before it goes off, then freeze it.
- Date stamps can get confusing, from 'use by' to 'best before'. You can find a guide with clear explanations here, so you can decide when something is safe to eat. Did you know around half of the food we throw away could actually be eaten?
3. Cooking and Serving
- Plan out your portions and only cook what you need.
- It's easy to overestimate things like pasta, rice and grains! Check out Love Food Hate Waste's useful porting planner here.
4. Leftovers
- Label your leftovers - naming and dating your food can help you keep track of what you have and what needs to be used first.
- When planning your meals, factor in leftovers too!
- Freeze or chill leftovers portion-sized so you only have to heat up what you need.
Non-edible food waste is any part of food that is not normally consumed or eaten, such as a banana peel, watermelon rind, corn cob, coffee grounds, or eggshell.
Unless banana peels and corn cobs are on the verge of becoming the next trendy snacks, we will always have non-edible food waste. What matters most with this type of food waste is how you dispose of it - put it in the Food Waste bins, instead of the general waste to ensure it goes to anaerobic digestion.
What can be Recycled in the Food Waste Bins?
Yes, please
✔ Food
✔ Teabags and ground coffee
✔ Peelings and fruit cores
✔ Plate scrapings
✔ Egg shells
No, thank you
✘ Clingfilm and plastic bags
✘ Liquid
✘ Cutlery and crockery
✘ Paper towels and serviettes
✘ Empty food containers such as yoghurt pots, take away containers, sandwich wrappers
✘ Empty tins and cans