Recycling
Recycling is the process of converting waste materials into new materials and objects. This concept often includes the recovery of energy from waste materials. The recyclability of a material depends on its ability to reacquire the properties it had in its original state.[1] It is an alternative to "conventional" waste disposal that can save material and help lower greenhouse gas emissions. It can also prevent the waste of potentially useful materials and reduce the consumption of fresh raw materials, reducing energy use, air pollution (from incineration) and water pollution (from landfilling).
This article is about recycling of waste materials. For recycling of waste energy, see Energy recycling.
Recycling is a key component of modern waste reduction and is the third component of the "Reduce, Reuse, and Recycle" waste hierarchy.[2][3] It promotes environmental sustainability by removing raw material input and redirecting waste output in the economic system.[4] There are some ISO standards related to recycling, such as ISO 15270:2008 for plastics waste and ISO 14001:2015 for environmental management control of recycling practice.
Recyclable materials include many kinds of glass, paper, cardboard, metal, plastic, tires, textiles, batteries, and electronics. The composting and other reuse of biodegradable waste—such as food and garden waste—is also a form of recycling.[5] Materials for recycling are either delivered to a household recycling center or picked up from curbside bins, then sorted, cleaned, and reprocessed into new materials for manufacturing new products.
In ideal implementations, recycling a material produces a fresh supply of the same material—for example, used office paper would be converted into new office paper, and used polystyrene foam into new polystyrene. Some types of materials, such as metal cans, can be remanufactured repeatedly without losing their purity.[6] With other materials, this is often difficult or too expensive (compared with producing the same product from raw materials or other sources), so "recycling" of many products and materials involves their reuse in producing different materials (for example, paperboard). Another form of recycling is the salvage of constituent materials from complex products, due to either their intrinsic value (such as lead from car batteries and gold from printed circuit boards), or their hazardous nature (e.g. removal and reuse of mercury from thermometers and thermostats).
History[edit]
Origins[edit]
Reusing materials has been a common practice for most of human history with recorded advocates as far back as Plato in the fourth century BC.[7] During periods when resources were scarce, archaeological studies of ancient waste dumps show less household waste (such as ash, broken tools, and pottery), implying that more waste was recycled in place of new material.[8] However, archaeological artefacts made from recyclable material, such as glass or metal, may neither be the original object nor resemble it, with the consequence that a successful ancient recycling economy can become invisible when recycling is synonymous with re-melting rather than reuse.[9]
Legislation[edit]
Supply[edit]
For a recycling program to work, a large, stable supply of recyclable material is crucial. Three legislative options have been used to create such supplies: mandatory recycling collection, container deposit legislation, and refuse bans. Mandatory collection laws set recycling targets for cities, usually in the form that a certain percentage of a material must be diverted from the city's waste stream by a target date. The city is responsible for working to meet this target.[5]
Container deposit legislation mandates refunds for the return of certain containers—typically glass, plastic and metal. When a product in such a container is purchased, a small surcharge is added that the consumer can reclaim when the container is returned to a collection point. These programs have succeeded in creating an average 80% recycling rate.[40] Despite such good results, the shift in collection costs from local government to industry and consumers has created strong opposition in some areas[5]—for example, where manufacturers bear the responsibility for recycling their products. In the European Union, the WEEE Directive requires producers of consumer electronics to reimburse the recyclers' costs.[41]
An alternative way to increase the supply of recyclates is to ban the disposal of certain materials as waste, often including used oil, old batteries, tires, and garden waste. This can create a viable economy for the proper disposal of the products. Care must be taken that enough recycling services exist to meet the supply, or such bans can create increased illegal dumping.[5]
Government-mandated demand[edit]
Four forms of legislation have also been used to increase and maintain the demand for recycled materials: minimum recycled content mandates, utilization rates, procurement policies, and recycled product labeling.[5]
Both minimum recycled content mandates and utilization rates increase demand by forcing manufacturers to include recycling in their operations. Content mandates specify that a certain percentage of a new product must consist of recycled material. Utilization rates are a more flexible option: Industries can meet their recycling targets at any point of their operations, or even contract out recycling in exchange for tradable credits. Opponents to these methods cite their large increase in reporting requirements, and claim that they rob the industry of flexibility.[5][42]
Governments have used their own purchasing power to increase recycling demand through "procurement policies". These policies are either "set-asides", which reserve a certain amount of spending for recycled products; or "price preference" programs that provide larger budgets when recycled items are purchased. Additional regulations can target specific cases: in the United States, for example, the Environmental Protection Agency mandates the purchase of oil, paper, tires and building insulation from recycled or re-refined sources whenever possible.[5]
The final government regulation toward increased demand is recycled product labeling. When producers are required to label their packaging with the amount of recycled material it contains (including the packaging), consumers can make more educated choices. Consumers with sufficient buying power can choose more environmentally conscious options, prompting producers to increase the recycled material in their products and increase demand. Standardized recycling labeling can also have a positive effect on the supply of recyclates when it specifies how and where the product can be recycled.[5]
Changes that have been demonstrated to increase recycling rates include:
In a study done by social psychologist Shawn Burn,[141] it was found that personal contact with individuals within a neighborhood is the most effective way to increase recycling within a community. In her study, she had 10 block leaders talk to their neighbors and persuade them to recycle. A comparison group was sent fliers promoting recycling. It was found that the neighbors that were personally contacted by their block leaders recycled much more than the group without personal contact. As a result of this study, Shawn Burn believes that personal contact within a small group of people is an important factor in encouraging recycling. Another study done by Stuart Oskamp[142] examines the effect of neighbors and friends on recycling. It was found in his studies that people who had friends and neighbors that recycled were much more likely to also recycle than those who did not have friends and neighbors that recycled.
Many schools have created recycling awareness clubs in order to give young students an insight on recycling. These schools believe that the clubs actually encourage students to not only recycle at school but at home as well.
Recycling of metals varies extremely by type. Titanium and lead have an extremely high recycling rates of over 90%. Copper and cobalt have high rates of recycling around 75%. Only about half of aluminum is recycled. Most of the remaining metals have recycling rates of below 35%, while 34 types of metals have recycling rates of under 1%.[143]
"Between 1960 and 2000, the world production of plastic resins increased 25 times its original amount, while recovery of the material remained below 5 percent."[144]: 131 Many studies have addressed recycling behaviour and strategies to encourage community involvement in recycling programs. It has been argued[145] that recycling behavior is not natural because it requires a focus and appreciation for long-term planning, whereas humans have evolved to be sensitive to short-term survival goals; and that to overcome this innate predisposition, the best solution would be to use social pressure to compel participation in recycling programs. However, recent studies have concluded that social pressure does not work in this context.[146] One reason for this is that social pressure functions well in small group sizes of 50 to 150 individuals (common to nomadic hunter–gatherer peoples) but not in communities numbering in the millions, as we see today. Another reason is that individual recycling does not take place in the public view.
Following the increasing popularity of recycling collection being sent to the same landfills as trash, some people kept on putting recyclables on the recyclables bin.[147]
Embracing a Circular Economy through Advanced Sorting Technologies[edit]
By extending the lifespan of goods, parts, and materials, a circular economy seeks to minimize waste and maximize resource utilization.[148] Advanced sorting techniques like optical and robotic sorting may separate and recover valuable materials from waste streams, lowering the requirement for virgin resources and accelerating the shift to a circular economy.
Community engagement, such as education and awareness campaigns, may support the acceptance of recycling and reuse programs and encourage the usage of sustainable practices. One can lessen our influence on the environment, save natural resources, and generate economic possibilities by adopting a circular economy using cutting-edge sorting technology and community engagement. According to Melati et al.,[149] to successfully transition to a circular economy, legislative and regulatory frameworks must encourage sustainable practices while addressing possible obstacles and difficulties in putting these ideas into action.