Recycling

From Trashwiki.org
Jump to: navigation, search
Trash.png This article or its section may require cleanup to meet Trashwiki's quality standards.

Please improve it if you can.


The international recycling symbol.
A recycling bin at a park in northern California.

Recycling involves processing used materials into new products in order to prevent the waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air (from incineration) and water (from landfilling) pollution by reducing the need for "conventional" waste disposal, and lower greenhouse gas emissions as compared to virgin production.<ref></ref><ref name="gar"/> Recycling is a key component of modern waste management and is the third component of the "Reduce, Reuse, Recycle" waste hierarchy.

Recyclable materials include glass, paper, metal, textiles, electronics (cell phones, computers) and plastics. Though similar, the composting of biodegradable waste – such as food or garden waste – is not typically considered recycling.<ref name="gar"></ref> These materials are either brought to a collection centre or picked-up from the curbside; and sorted, cleaned and reprocessed into new products bound for manufacturing.

However, critics of recycling claim that it often wastes more resources than it saves, especially in cases where it is mandated by government.

See also precycling.

Background

In the United States, recycling facilities earn estimated revenues of $2,981 million a year. Growth has exceeded 7% per year for the past five years (from 2003 to 2008) due to rising waste volumes and increasing recyclable commodity prices. New initiatives can change the industry. For example, in California and New York, moves to raise the requirements for the set amount of waste to be diverted from the waste stream from 50 percent to 75 percent can produce healthy profits for companies that collect and process recyclables.<ref>March 2008, Cashing in on Climate Change, IBISWorld</ref>

Cost-benefit analysis

Environmental effects of recycling<ref>Unless otherwise indicated, this data is taken from , which attributes, "Garbage Solutions: A Public Officials Guide to Recycling and Alternative Solid Waste Management Technologies, as cited in Energy Savings from Recycling, January/February 1989; and Worldwatch 76 Mining Urban Wastes: The Potential for Recycling, April 1987."</ref>
Material Energy Savings Air Pollution Savings
Aluminum 95%<ref name="gar"/><ref name="economistrecycle"/> 95%<ref name="gar"/><ref name="WasteOnline"/>
Cardboard 24%
Glass 5-30% 20%
Paper 40%<ref name="economistrecycle"/> 73%
Plastics 70%<ref name="economistrecycle"/>
Steel 60%<ref name="economisttruth"/>

There is some debate over whether recycling is economically efficient. Municipalities often see fiscal benefits from implementing recycling programs, largely due to the reduced landfill costs.<ref>Lavee D. (2007). Is Municipal Solid Waste Recycling Economically Efficient? Environmental Management.</ref> A study conducted by the Technical University of Denmark found that in 83% of cases, recycling is the most efficient method to dispose of household waste.<ref name="economisttruth"></ref><ref name="economistrecycle"></ref> In addition to fiscal benefits, justification for recycling lie in what economists call externalities, unpriced costs and benefits which accrue to individuals outside of private transactions. Examples include: increased air pollution and greenhouse gases from incineration, reduced hazardous waste leaching from landfills, reduced energy consumption, and reduced waste and resource consumption, which leads to a reduction in environmentally damaging mining and timber activity. Without mechanisms such as taxes or subsidies to internalize externalities, businesses will ignore them despite the costs imposed on society. In order to make such non-fiscal benefits economically relevant, advocates have pushed for legislative action to increase the demand for recycled materials.<ref name="gar"/> The United States Environmental Protection Agency (EPA) has concluded in favour of recycling, saying that recycling efforts reduced the country's carbon emissions by a net 49 million metric tonnes in 2005.<ref name="economisttruth"/> In the United Kingdom, the Waste and Resources Action Programme stated that Great Britain's recycling efforts reduce CO2 emissions by 10-15 million tonnes a year.<ref name="economisttruth"/> Recycling is more efficient in densely populated areas, as there are economies of scale involved.<ref name="gar"/>

Certain requirements must be met in order for recycling to be economically feasible and environmentally effective. These include an adequate source of recyclates, a system to extract those recyclates from the waste stream, a nearby factory capable of reprocessing the recyclates, and a potential demand for the recycled products. These last two requirements are often overlooked—without both an industrial market for production using the collected materials and a consumer market for the manufactured goods, recycling is incomplete and in fact only "collection".<ref name="gar"/>

Trade in recyclates

Computers being collected for recycling at a pickup event in Olympia, Washington, United States.

Certain countries trade in unprocessed recyclates. Some have complained that the ultimate fate of recyclates sold to another country is unknown and they may end up in landfill instead of reprocessed. According to one report, in America, 50-80% of computers destined for recycling are actually not recycled.<ref>[http://www.usatoday.com/tech/news/2002/02/25/computer-waste.htm Much toxic computer waste lands in Third World</ref> However, Pieter van Beukering, an economist specialising in waste imports of China and India, believes that it is unlikely that bought materials would merely be dumped in landfill: he also claims that the import of recyclates allows for large-scale reprocessing, improving both the fiscal and environmental return through economies of scale.<ref name="economisttruth"/> There are reports of illegal-waste imports to China being dismantled and recycled solely for monetary gain, without consideration for workers' health or environmental damage. Though the Chinese government has banned these practices, it has not been able to eradicate them completely, nor estimate the amount of illegal recycling still occurring.<ref name="economisttruth"/>

Certain regions have difficulty using or exporting as much of a material as they recycle. This problem is most prevalent with glass: both Britain and the US import large quantities of wine bottled in green glass. Though much of this glass is sent to be recycled, outside the American Midwest there is not enough wine production to use all of the reprocessed material. The extra must be downcycled into building materials or re-inserted into the regular waste stream.<ref name="economisttruth"/><ref name="gar"/>

Similarly, the northwestern United States has difficultly finding markets for recycled newspaper, given the large number of pulp mills in the region as well as the proximity to Asian markets. In other areas of the US, however, demand for used newsprint has seen wide fluctuation.<ref name="gar"/>

In some US states, a program called RecycleBank pays people with coupons to recycle, receiving money from local municipalities for the reduction in landfill space which must be purchased. It uses a single stream process in which all material is automatically sorted.<ref>Bonnie DeSimone. (2006). Rewarding Recyclers, and Finding Gold in the Garbage. New York Times.</ref>

Legislation

Supply

In order for a recycling program to work, having a large, stable supply of recyclable material is crucial. Three legislative options have been used to create such a supply: mandatory recycling collection, container deposit legislation, and refuse bans. Mandatory collection laws set recycling targets for cities to aim for, 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 then responsible for working to meet this target.<ref name="gar"/>

Container deposit legislation involves offering a refund 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 to the price. This surcharge can be reclaimed by the consumer if the container is returned to a collection point. These programs have been very successful, often resulting in an 80% recycling rate. Despite such good results, the shift in collection costs from local government to industry and consumers has created strong opposition to the creation of such programs in some areas.<ref name="gar"/>

A third method of increase supply of recyclates is to ban the disposal of certain materials as waste, often including used oil, old batteries, tires and garden waste. One aim of this method is to create a viable economy for proper disposal of banned products. Care must be taken that enough of these recycling services exist, or such bans simply lead to increased illegal dumping.<ref name="gar"/>

Government-mandated demand

Legislation has also been used to increase and maintain a demand for recycled materials. Four methods of such legislation exist: minimum recycled content mandates, utilisation rates, procurement policies, recycled product labelling.<ref name="gar"/>

Both minimum recycled content mandates and utilisation rates increase demand directly 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. Utilisation rates are a more flexible option: industries are permitted to meet the recycling targets at any point of their operation or even contract recycling out in exchange for tradeable credits. Opponents to both of these methods point to the large increase in reporting requirements they impose, and claim that they rob industry of necessary flexibility.<ref name="gar"/><ref name="DeLong"></ref>

Governments have used their own purchasing power to increase recycling demand through what are called "procurement policies". These policies are either "set-asides", which earmark a certain amount of spending solely towards recycled products, or "price preference" programs which provide a larger budget when recycled items are purchased. Additional regulations can target specific cases: in the US, for example, the Environmental Protection Agency mandates the purchase of oil, paper, tires and building insulation from recycled or re-refined sources whenever possible.<ref name="gar"/>

The final government regulation towards increased demand is recycled product labeling. When producers are required to label their packaging with amount of recycled material in the product (including the packaging), consumers are better able to make educated choices. Consumers with sufficient buying power can then choose more environmentally conscious options, prompt producers to increase the amount of recycled material in their products, and indirectly increase demand. Standardised recycling labelling can also have a positive effect on supply of recyclates if the labelling includes information on how and where the product can be recycled.<ref name="gar"/>

Process

Collection

A number of different systems have been implemented to collect recyclates from the general waste stream. These systems tend to lie along the spectrum of trade-off between public convenience and government ease and expense. The three main categories of collection are "drop-off centres", "buy-back centres" and "curbside collection".<ref name="gar"/>

Drop-off centres require the waste producer carry the recyclates to a central location, either an installed or mobile collection station or the reprocessing plant itself. They are the easiest type of collection to establish, but suffer from low and unpredictable throughput. Buy-back centres differ in that the cleaned recyclates are purchased, thus providing a clear incentive for use and creating a stable supply. The post-processed material can then be sold on, hopefully creating a profit. Unfortunately government subsidies are necessary to make buy-back centres a viable enterprise, as according to the United States Nation Solid Wastes Management Association it costs on average US$50 to process a ton of material, which can only be resold for US$30.<ref name="gar"/>

Curbside collection

Curbside collection encompasses many subtly different systems, which differ mostly on where in the process the recyclates are sorted and cleaned. The main categories are mixed waste collection, commingled recyclables and source separation.<ref name="gar"/> A waste collection vehicle generally picks up the waste.

At one end of the spectrum is mixed waste collection, in which all recyclates are collected mixed in with the rest of the waste, and the desired material is then sorted out and cleaned at a central sorting facility. This results in a large amount of recyclable waste, paper especially, being too soiled to reprocess, but has advantages as well: the city need not pay for a separate collection of recyclates and no public education is needed. Any changes to which materials are recyclable is easy to accommodate as all sorting happens in a central location.<ref name="gar"/>

In a Commingled or single-stream system, all recyclables for collection are mixed but kept separate from other waste. This greatly reduces the need for post-collection cleaning but does require public education on what materials are recyclable.<ref name="gar"/><ref name="economisttruth"/>

Source separation is the other extreme, where each material is cleaned and sorted prior to collection. This method requires the least post-collection sorting and produces the purest recyclates, but incurs additional operating costs for collection of each separate material. An extensive public education program is also required, which must be successful if recyclate contamination is to be avoided.<ref name="gar"/>

Source separation used to be the preferred method due to the high sorting costs incurred by commingled collection. Advances in sorting technology (see sorting below), however, have lowered this overhead substantially—many areas which had developed source separation programs have since switched to comingled collection.<ref name="economisttruth"/>

Sorting

Once commingled recyclates are collected and delivered to a central collection facility, the different types of materials must be sorted. This is done in a series of stages, many of which involve automated processes such that a truck-load of material can be fully sorted in less than an hour.<ref name="economisttruth"/> Some plants can now sort the materials automatically, known as Single Stream. A 30% increase in recycling rates has been seen in the areas where these plants exist.<ref>ScienceDaily. (2007). Recycling Without Sorting Engineers Create Recycling Plant That Removes The Need To Sort.</ref>

Initially, the commingled recyclates are removed from the collection vehicle and placed on a conveyor belt spread out in a single layer. Large pieces of cardboard and plastic bags are removed by hand at this stage, as they can cause later machinery to jam.<ref name="economisttruth"/>

Next, automated machinery separates the recyclates by weight, splitting lighter paper and plastic from heavier glass and metal. Cardboard is removed from the mixed paper and the most common types of plastic (PET and HDPE) are collected. This separation is usually done by hand, but has become automated in some sorting centres: a spectroscopic scanner is used to differentiate between different types of paper and plastic based on the absorbed wavelengths, and subsequently divert each material into the proper collection channel.<ref name="economisttruth"/>

Strong magnets are used to separate out ferrous metals (tin-plated or steel cans), while non-ferrous metals are ejected by magnetic eddy currents. A rotating magnetic field induces an electric current around the aluminum cans, which in turn creates a magnetic eddy current inside the cans. This magnetic eddy current is repulsed by the large magnetic field, and the cans are ejected from the rest of the recyclate stream.<ref name="economisttruth"/>

Finally, glass must be sorted by hand based on its color: brown, amber, green or clear.<ref name="economisttruth"/>

Common recyclables

Many different materials can be recycled but each type requires a different technique.

Aggregates and concrete

Concrete aggregate collected from demolition sites is put through a crushing machine, often along with asphalt, bricks, dirt, and rocks. Smaller pieces of concrete are used as gravel for new construction projects. Crushed recycled concrete can also be used as the dry aggregate for brand new concrete if it is free of contaminants. This reduces the need for other rocks to be dug up, which in turn saves trees and habitats.<ref></ref>

Some batteries contain toxic heavy metals, making recycling or proper disposal a high priority

Batteries

The large variation in size and type of batteries makes their recycling extremely difficult: they must first be sorted into similar kinds and each kind requires an individual recycling process. Additionally, older batteries contain mercury and cadmium, harmful materials which must be handled with care. Because of their potential environmental damage, proper disposal of used batteries is required by law in many areas. Unfortunately, this mandate has been difficult to enforce.<ref name="batt"></ref>

Lead-acid batteries, like those used in automobiles, are relatively easy to recycle and many regions have legislation requiring vendors to accept used products. In the United States, the recycling rate is 90%, with new batteries containing up to 80% recycled material.<ref name="batt"/>

Garden waste for composting

Biodegradable waste

Kitchen, garden and other green waste can be recycled into useful material by composting. This process allows natural aerobic bacteria to break down the waste into fertile topsoil. Much composting is done on a household scale, but municipal green-waste collection programs also exist. These programs can supplement their funding by selling the topsoil produced.

Clothing

Recycling clothes via consignment or swapping has become increasingly popular. In a clothing swap, a group of people gather at a venue to exchange clothes amongst each other. In organizations like Clothing Swap, Inc., unclaimed clothing is donated to a local charity.

Electronics disassembly and reclamation

The direct disposal of electrical equipment—such as old computers and mobile phones—is banned in many areas due to the toxic contents of certain components. The recycling process works by mechanically separating the metals, plastics and circuit boards contained in the appliance. When this is done on a large scale at an electronic waste recycling plant, component recovery can be achieved in a cost-effective manner.

Ferrous metals

Iron and steel are the world's most recycled materials, and among the easiest materials to reprocess, as they can be separated magnetically from the waste stream. Recycling is via a steelworks: scrap is either remelted in an electric arc furnace (90-100% scrap), or used as part of the charge in a Basic Oxygen Furnace (around 25% scrap).<ref> </ref> Any grade of steel can be recycled to top quality new metal, with no 'downgrading' from prime to lower quality materials as steel is recycled repeatedly. 42% of crude steel produced is recycled material.<ref></ref>

Non-ferrous metals

Aluminum is one of the most efficient and widely-recycled materials.<ref>DRLP Fact Sheets</ref><ref>Environmental Protection Agency Frequently Asked Questions about Recycling and Waste Management</ref> Aluminum is shredded and grounded into small pieces or crushed into bales. These pieces or bales are melted in an aluminum smelter to produce molten aluminum. By this stage the recycled aluminum is indistinguishable from virgin aluminum and further processing is identical for both. This process does not produce any change in the metal, so aluminum can be recycled indefinitely.

Recycling aluminum saves 95% of the energy cost of processing new aluminum.<ref name="economistrecycle"/> This is because the temperature necessary for melting recycled, nearly pure, aluminum is 600 °C, while to extract mined aluminum from its ore requires 900 °C. To reach this higher temperature, much more energy is needed, leading to the high environmental benefits of aluminum recycling.<ref name='WasteOnline'></ref>

Glass

Glass bottles and jars are gathered by a curbside collection truck and bottle banks, where the glass may be sorted into color categories. The collected glass cullet is taken to a glass recycling plant where it is monitored for purity and contaminants are removed. The cullet is crushed and added to a raw material mix in a melting furnace. It is then mechanically blown or molded into new jars or bottles. Glass cullet is also used in the construction industry for aggregate and glassphalt. Glassphalt is a road-laying material which comprises around 30% recycled glass. Glass can be recycled indefinitely as its structure does not deteriorate when reprocessed.

Paper

Paper can be recycled by reducing it to pulp and combing it with pulp from newly harvested wood. As the recycling process causes the paper fibres to breakdown, each time paper is recycled its quality decreases. This means that either a higher percentage of new fibres must be added, or the paper downcycled into lower quality products. Any writing or colouration of the paper must first be removed by deinking, which also removes fillers, clays, and fiber fragments.<ref name="paper"></ref>

Almost all paper can be recycled today, but some types are harder to recycle than others. Papers coated with plastic or aluminum foil, and papers that are waxed, pasted, or gummed are usually not recycled because the process is too expensive. Gift wrap paper also cannot be recycled due to its already poor quality.<ref name="paper"/>

Sometimes recyclers ask for the removal of the glossy inserts from newspapers because they are a different type of paper. Glossy inserts have a heavy clay coating that some paper mills cannot accept. Most of the clay is removed from the recycled pulp as sludge which must be disposed of. If the coated paper is 20% by weight clay, then each ton of glossy paper produces more than 200 kg of sludge and less than 800 kg of fiber.<ref name="paper"/>

Plastic

Plastic shipping crates

Plastic recycling is the process of recovering scrap or waste plastics and reprocessing the material into useful products. Compared to glass or metallic materials, plastic poses unique challenges. Because of the massive number of types of plastic, they each carry a resin identification code, and must be sorted before they can be recycled. This can be costly; while metals can be sorted using electromagnets, no such 'easy sorting' capability exists for plastics. In addition to this, while labels do not need to be removed from bottles for recycling, lids are often made from a different kind of non-recyclable plastic.

A brown cloth

Textiles

When considering textile recycling one must understand what the material consists of. Most textiles are composites of cotton (biodegradable material) and synthetic plastics. The textile's composition will affect its durability and method of recycling.

Workers sort and separate collected textiles into good quality clothing and shoes which can be reused or worn. There is a trend of moving these facilities from developed countries to developing countries either for charity or sold at a cheaper price.<ref></ref> Many international organisations collect used textiles from developed countries as a donation to those third world countries. This recycling practise is encouraged because it helps to reduce unwanted waste while providing clothing to those in need.<ref></ref> Damaged textiles are further sorted into grades to make industrial wiping cloths and for use in paper manufacture or material suitable for fibre reclamation and filling products. If textile reprocessors receive wet or soiled clothes however, these may still be disposed of in a landfill, as the washing and drying facilities are not present at sorting units.<ref></ref>

Fibre reclamation mills sort textiles according to fibre type and colour. Colour sorting eliminates the need to re-dye the recycled textiles. The textiles are shredded into "shoddy" fibres and blended with other selected fibres, depending on the intended end use of the recycled yarn. The blended mixture is carded to clean and mix the fibres and spun ready for weaving or knitting. The fibres can also be compressed for mattress production. Textiles sent to the flocking industry are shredded to make filling material for car insulation, roofing felts, loudspeaker cones, panel linings and furniture padding.

A stack of wooden pallets awaits reuse or recycling.

Timber

Recycling timber has become popular due to its image as an environmentally friendly product, with consumers commonly believing that by purchasing recycled wood the demand for green timber will fall and ultimately benefit the environment. Greenpeace also view recycled timber as an environmentally friendly product, citing it as the most preferable timber source on their website. The arrival of recycled timber as a construction product has been important in both raising industry and consumer awareness towards deforestation and promoting timber mills to adopt more environmentally friendly practices.<ref></ref>

Wood recycling is a subject which has in recent years taken an ever greater role in our lives. The problem, however, is that although many local authorities like the idea of recycling, they do not fully support it. One of the countless examples, which has been in the news is the concept of actually recycling wood which is growing in the cities. Namely, recycling timber, trees and other sources.<ref>[1], www.citywood.co.uk, Retrieved 24.11.06</ref>

Other Techniques

Several other materials are also commonly recycled, frequently at an industrial level.

Ship breaking is one example that has associated environmental, health, and safety risks for the area where the operation takes place; balancing all these considerations is an environmental justice problem.

Tire recycling is also common. Used tires can be added to asphalt for producing road surfaces or to make rubber mulch used on playgrounds for safety. They are also often used as the insulation and heat absorbing/releasing material in specially constructed homes known as earthships.

Sustainable design

Much of the difficulty inherent in recycling comes from the fact that most products are not designed with recycling in mind. The concept of sustainable design aims to solve this problem, and was first laid out in the book "Cradle to Cradle: Remaking the Way We Make Things" by architect William McDonough and chemist Michael Braungart. They suggest that every product (and all packaging they require) should have a complete "closed-loop" cycle mapped out for each component—a way in which every component will either return to the natural ecosystem through biodegradation or be recycled indefinitely.<ref name="economisttruth"/>

As with environmental economics, care must be taken to ensure a complete view of the costs and benefits involved. For example, cardboard packaging for food products is more easily recycled than plastic, but is heavier to ship and may result in more waste from spoilage.<ref name="Tierney"></ref>

History

See article in Wikipedia on history of recycling.

Criticism

In a 1996 article in The New York Times, John Tierney claimed that government mandated recycling wastes more resources than it saves.<ref>Recycling Is Garbage The New York Times, June 30, 1996, by John Tierney </ref> Some highlights from the article:

  • In cases where recycling truly does save resources, such as with large scraps of aluminum, this will be reflected in market prices, and voluntary recycling will take place. Thus, there is no need for the government to mandate it.
  • Tree farmers plant more trees than they cut down.
  • Government mandated recycling is more expensive than putting the garbage into landfills, which means that this recycling uses up more resources than it saves.
  • Some small towns with landfills are happy to import garbage from other cities and states because it provides jobs and tax revenue.
  • Today's modern landfills are much cleaner and safer, and much less likely to leak and pollute than the landfills of the past.
  • Regarding the claim that the U.S. is running out of landfill space, Tierney wrote, "A. Clark Wiseman, an economist at Gonzaga University in Spokane, Wash., has calculated that if Americans keep generating garbage at current rates for 1,000 years, and if all their garbage is put in a landfill 100 yards deep, by the year 3000 this national garbage heap will fill a square piece of land 35 miles on each side. This doesn't seem a huge imposition in a country the size of America. The garbage would occupy only 5 percent of the area needed for the national array of solar panels proposed by environmentalists. The millennial landfill would fit on one-tenth of 1 percent of the range land now available for grazing in the continental United States. And if it still pains you to think of depriving posterity of that 35-mile square, remember that the loss will be only temporary. Eventually, like previous landfills, the mounds of trash will be covered with grass and become a minuscule addition to the nation's 150,000 square miles of parkland."

Tierney's article received a referenced critique from the Environmental Defense Fund, which noted that "the article relied heavily on quotes and information supplied by a group of consultants and think tanks that have strong ideological objections to recycling".<ref name=edf></ref>

In 2003, the city of Santa Clarita, California was paying $28 per ton to put garbage into a landfill. The city then adopted a mandatory diaper recycling program that cost $1,800 per ton.<ref>Diaper Recycling in California The Free Liberal, September 08, 2003</ref>

In a 2007 article, Michael Munger, the Chair of Political Science at Duke University, wrote, "... if recycling is more expensive than using new materials, it can't possibly be efficient... There is a simple test for determining whether something is a resource... or just garbage... If someone will pay you for the item, it's a resource... But if you have to pay someone to take the item away... then the item is garbage."<ref>http://econlib.org/library/Columns/y2007/Mungerrecycling.html "Think Globally, Act Irrationally: Recycling</ref>

In a 2002 article for The Heartland Institute, Jerry Taylor, director of natural resource studies at the Cato Institute, wrote, "If it costs X to deliver newly manufactured plastic to the market, for example, but it costs 10X to deliver reused plastic to the market, we can conclude the resources required to recycle plastic are 10 times more scarce than the resources required to make plastic from scratch. And because recycling is supposed to be about the conservation of resources, mandating recycling under those circumstances will do more harm than good."<ref>Recycling: It's a bad idea in New York The Heartland Institute, May 1, 2002</ref>

In 2002, WNYC reported that 40% of the garbage that New York City residents separated for recycling actually ended up in landfills.<ref>City Council Holds Hearings on Saving Recycling, WNYC, April 18, 2002</ref>

See also

Web globe.png This article contains text from the Wikipedia article on Recycling.