What are biowastes
Biowastes include the biodegradable parts of municipal wastes including food and garden waste, paper, cardboard, some textiles and wood. It also includes livestock manures and slurry, treated sewage sludge, organic industrial waste (such as paper and textiles) and compost.
Recovering value from biowastes
Avoiding or reducing the production of biowastes is usually the most effective solution for the environment. However, unavoidable biowastes should be managed in ways which recover the maximum value while minimising their environmental impact.
Landfilling waste should be avoided wherever possible: the organic carbon in biowastes is converted to carbon dioxide and methane – a potent greenhouse gas with 23 times the global warming potential of carbon dioxide.
Different ways to recover value from biowastes
Some methods recover value by recycling nutrients and organic carbon into the soil. These include:
- direct application of biowastes such as paper pulp and brewery wastes to agricultural land;
- composting which has traditionally been used to recycle garden and similar wastes but is also suitable for food wastes and soiled or wet paper and cardboard;
- anaerobic digestion which can produce two valuable outputs. One is digestate which can be used in similar ways to compost and the other is biogas which can be used to produce energy. This is generally most suitable for wet biowastes and not for woody wastes.
Some methods involve recycling materials in other ways, including:
- paper recycling from clean, dry waste paper;
- wood recycling from clean, uncontaminated wood.
Other methods use thermal technologies, which involve energy recovery at elevated temperatures. These technologies include:
- incineration which can recover heat and/or power, for example from the ‘residual’ matter left over from households after wastes for recycling have been removed;
- pyrolysis and gasification, producing gaseous and liquid fuels from dry biowastes, for example from wood.
Further information
Read further information and see our views on some of the most pressing issues concerning biowastes:
Energy from Waste
We strongly support the ambitious target of generating 15 per cent of the UK’s energy from renewables by 2020.
