Unit 6: Materials Recovery and Circular Economy
Expert-defined terms from the Professional Certificate in Waste-to-Energy Conversion course at London School of Business and Administration. Free to read, free to share, paired with a globally recognised certification pathway.
Anoxic Digestion #
A type of anaerobic digestion that takes place in the absence of oxygen. This process is used to break down organic materials in waste, producing biogas and a nutrient-rich digestate.
Biomass #
Organic material, such as plant and animal waste, that can be converted into fuel or energy through various processes, including anaerobic digestion, combustion, and gasification.
Bioreactor #
A tank or container used in anaerobic digestion where organic waste is broken down by microorganisms in the absence of oxygen.
Circular Economy #
An economic system aimed at eliminating waste and the continual use of resources. In a circular economy, products and materials are kept in use for as long as possible, and waste is reduced to a minimum.
Composting #
A biological process that breaks down organic waste, such as food scraps and yard waste, into a nutrient-rich soil amendment.
Construction and Demolition (C&D) Waste #
Waste generated from the construction, renovation, and demolition of buildings, roads, and other infrastructure.
De #
packaging: The process of separating and removing packaging materials from waste streams, such as food waste, in order to facilitate recycling and recovery of the underlying materials.
Demolition Waste #
Waste generated from the demolition of buildings, roads, and other infrastructure.
Downcycling #
The process of converting waste materials into new products of lower quality or functionality than the original product.
Energy from Waste (EfW) #
The process of generating energy, such as electricity or heat, from the combustion of waste materials.
Energy Recovery #
The process of capturing and utilizing the energy contained in waste materials, such as through incineration or anaerobic digestion.
Ferrous Metals #
Metals that contain iron, such as steel and cast iron.
Gasification #
A process that converts organic materials into a gas mixture, called syngas, through partial oxidation at high temperatures.
Greenhouse Gases (GHGs) #
Gases, such as carbon dioxide and methane, that trap heat in the atmosphere and contribute to global warming and climate change.
Hazardous Waste #
Waste that poses a threat to human health and the environment, and is regulated by laws and regulations.
Industrial Symbiosis #
The practice of businesses working together to exchange waste materials and by-products, creating a closed-loop system where waste is minimized and resources are conserved.
Incineration #
The process of burning waste materials in the presence of oxygen, resulting in the production of ash, flue gas, and heat.
Landfill Gas #
A gas produced by the decomposition of organic waste in landfills. Landfill gas is composed primarily of methane and carbon dioxide.
Leachate #
A liquid that forms when rainwater filters through waste in a landfill, picking up contaminants along the way.
Life #
Cycle Assessment (LCA): A method for evaluating the environmental impacts of a product or process from cradle to grave, including raw material extraction, manufacturing, use, and disposal.
Mechanical Biological Treatment (MBT) #
A waste treatment process that combines mechanical and biological methods to reduce the volume and increase the recyclability of waste.
Mechanical Sorting #
The process of using machines and equipment to separate waste into different streams, such as metals, plastics, and organics.
Metals #
A category of materials that includes ferrous and non-ferrous metals, such as aluminum, copper, and zinc.
Methane #
A potent greenhouse gas, composed of one carbon atom and four hydrogen atoms, that is produced by the anaerobic digestion of organic materials.
Municipal Solid Waste (MSW) #
Waste generated by households and businesses, including food waste, paper, plastics, metals, and glass.
Non #
ferrous Metals: Metals that do not contain iron, such as aluminum, copper, and zinc.
Organic Waste #
Waste materials that are composed of carbon-based compounds, such as food scraps, yard waste, and paper.
Plastics #
A category of materials made from synthetic polymers, including polyethylene, polypropylene, and polyvinyl chloride.
Post #
consumer Waste: Waste generated by consumers after the end of a product's useful life.
Pre #
consumer Waste: Waste generated during the manufacturing process, before a product reaches the end-user.
Pyrolysis #
A process that decomposes organic materials in the absence of oxygen, resulting in the production of a gas mixture, liquids, and solids.
Recyclable Materials #
Materials that can be collected, processed, and manufactured into new products, reducing the need for raw materials and energy.
Recycling #
The process of collecting, processing, and manufacturing waste materials into new products, reducing the need for raw materials and energy.
Refuse #
Derived Fuel (RDF): A fuel made from processed municipal solid waste, typically consisting of combustible materials such as paper, plastics, and textiles.
Remanufacturing #
The process of restoring a product to its original condition, using a combination of new and recycled parts.
Renewable Energy #
Energy generated from sources that are naturally replenished, such as wind, solar, and hydro power.
Resource Efficiency #
The practice of using resources, including materials and energy, in a way that minimizes waste and maximizes value.
Resource Recovery #
The process of extracting valuable materials and energy from waste, reducing the need for landfilling and incineration.
Secondary Materials #
Materials that have been recovered from waste and are used as inputs in the production of new products.
Sorting #
The process of separating waste into different streams, such as metals, plastics, and organics, in order to facilitate recycling and recovery.
Sustainable Materials Management (SMM) #
A systematic approach to managing materials, including their extraction, production, use, and disposal, in a way that minimizes environmental impacts and maximizes resource efficiency.
Upcycling #
The process of converting waste materials into new products of higher quality or functionality than the original product.
Waste #
to-Energy (WtE): The process of generating energy, such as electricity or heat, from the combustion of waste materials.
Waste Management #
The practice of collecting, transporting, processing, and disposing of waste in a way that minimizes environmental impacts and maximizes resource efficiency.
Waste Minimization #
The practice of reducing the amount of waste generated, through source reduction, reuse, and recycling.
Waste Prevention #
The practice of reducing the amount of waste generated, through source reduction and reuse.
Waste Reduction #
The practice of reducing the amount of waste generated, through source reduction, reuse, and recycling.
Waste Stream #
A flow of waste materials, such as municipal solid waste, construction and demolition waste, or industrial waste, that is generated and managed in a specific context.
Zero Waste #
A goal of reducing waste to as close to zero as possible, through a combination of source reduction, reuse, recycling, and composting.