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. 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 and water pollution.
Recycling is a key component of modern waste reduction and represents the third step in the "Reduce, Reuse, and Recycle" waste hierarchy, contributing to environmental sustainability and resource conservation. It promotes environmental sustainability by removing raw material input and redirecting waste output in the economic system. 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. 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. With other materials, this is often difficult or too expensive, so "recycling" of many products and materials involves their reuse in producing different materials. Another form of recycling is the salvage of constituent materials from complex products, due to either their intrinsic value, or their hazardous nature.
History
Origins
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. During periods when resources were scarce, archaeological studies of ancient waste dumps show less household waste, implying that more waste was recycled in place of new material. 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.In pre-industrial times, there is evidence of scrap bronze and other metals being collected in Europe and melted down for continuous reuse. Paper recycling was first recorded in 1031 when Japanese shops sold repulped paper. In Britain dust and ash from wood and coal fires was collected by "dustmen" and downcycled as a base material for brick making. These forms of recycling were driven by the economic advantage of obtaining recycled materials instead of virgin material, and the need for waste removal in ever-more-densely populated areas. In 1813, Benjamin Law developed the process of turning rags into "shoddy" and "mungo" wool in Batley, Yorkshire, which combined recycled fibers with virgin wool. The West Yorkshire shoddy industry in towns such as Batley and Dewsbury lasted from the early 19th century to at least 1914.
Industrialization spurred demand for affordable materials. In addition to rags, ferrous scrap metals were coveted as they were cheaper to acquire than virgin ore. Railroads purchased and sold scrap metal in the 19th century, and the growing steel and automobile industries purchased scrap in the early 20th century. Many secondary goods were collected, processed and sold by peddlers who scoured dumps and city streets for discarded machinery, pots, pans, and other sources of metal. By World War I, thousands of such peddlers roamed the streets of American cities, taking advantage of market forces to recycle post-consumer materials into industrial production.
Manufacturers of beverage bottles, including Schweppes, began offering refundable recycling deposits in Great Britain and Ireland around 1800. An official recycling system with refundable deposits for bottles was established in Sweden in 1884, and for aluminum beverage cans in 1982; it led to recycling rates of 84–99%, depending on type.
Wartime
New chemical industries created in the late 19th century both invented new materials and promised to transform valueless into valuable materials. Proverbially, you could not make a silk purse of a sow's ear—until the US firm Arthur D. Little published in 1921 "On the Making of Silk Purses from Sows' Ears", its research proving that when "chemistry puts on overalls and gets down to business new values appear. New and better paths are opened to reach the goals desired."Recycling—or "salvage", as it was then usually known—was a major issue for governments during World War II, where financial constraints and significant material shortages made it necessary to reuse goods and recycle materials. These resource shortages caused by the world wars, and other such world-changing events, greatly encouraged recycling. It became necessary for most homes to recycle their waste, allowing people to make the most of what was available. Recycling household materials also meant more resources were left available for war efforts. Massive government campaigns, such as the National Salvage Campaign in Britain and the Salvage for Victory campaign in the United States, occurred in every fighting nation, urging citizens to donate metal, paper, rags, and rubber as a patriotic duty.
Post-World War II
A considerable investment in recycling occurred in the 1970s due to rising energy costs. Recycling aluminium uses only 5% of the energy of virgin production. Glass, paper and other metals have less dramatic but significant energy savings when recycled.Although consumer electronics have been popular since the 1920s, recycling them was almost unheard of until early 1991. The first electronic waste recycling scheme was implemented in Switzerland, beginning with collection of old refrigerators, then expanding to cover all devices. When these programs were created, many countries could not deal with the sheer quantity of e-waste, or its hazardous nature, and began to export the problem to developing countries without enforced environmental legislation. Demand for electronic waste in Asia began to grow when scrapyards found they could extract valuable substances such as copper, silver, iron, silicon, nickel, and gold during the recycling process. The 2000s saw a boom in both the sales of electronic devices and their growth as a waste stream: In 2002, e-waste grew faster than any other type of waste in the EU. This spurred investment in modern automated facilities to cope with the influx, especially after strict laws were implemented in 2003.
As of 2014, the European Union had about 50% of world share of waste and recycling industries, with over companies employing people and a turnover of €24 billion. EU countries are mandated to reach recycling rates of at least 50%; leading countries are already at around 65%. The overall EU average was 39% in 2013
and is rising steadily, to 45% in 2015.
In 2015, the United Nations General Assembly set 17 Sustainable Development Goals. Goal 12, Responsible Consumption and Production, specifies 11 targets "to ensure sustainable consumption and production patterns". The fifth target, Target 12.5, is defined as substantially reducing waste generation by 2030, indicated by the National Recycling Rate.
In 2018, changes in the recycling industry have sparked a global "crisis". On 31 December 2017, China announced its "National Sword" policy, setting new standards for imports of recyclable material and banning materials deemed too "dirty" or "hazardous". The new policy caused drastic disruptions in the global recycling market, and reduced the prices of scrap plastic and low-grade paper. Exports of recyclable materials from G7 countries to China dropped dramatically, with many shifting to countries in southeast Asia. This generated significant concern about the recycling industry's practices and environmental sustainability. The abrupt shift caused countries to accept more materials than they could process, and raised fundamental questions about shipping waste from developed countries to countries with few environmental regulations—a practice that predated the crisis.
Health and environmental impact
Health impact
E-waste
According to the WHO, "Every year millions of electrical and electronic devices are discarded... a threat to the environment and to human health if they are not treated, disposed of, and recycled appropriately. Common items... include computers... e-waste are recycled using environmentally unsound techniques and are likely stored in homes and warehouses, dumped, exported or recycled under inferior conditions. When e-waste is treated using inferior activities, it can release as many as 1000 different chemical substances... including harmful neurotoxicants such as lead." A paper in the journal Sustainable Materials & Technologies remarks upon the difficulty of managing e-waste, particularly from home automation products, which, due to their becoming obsolete at a high rate, are putting increasing strain on recycling systems, which have not adapted to meet the recycling needs posed by this type of product.Slag recycling
Copper slag is obtained when copper and nickel ores are recovered from their source ores using a pyrometallurgical process, and these ores usually contain other elements which include iron, cobalt, silica, and alumina. An estimate of 2.2–3 tons of copper slag is generated per ton of copper produced, resulting in around 24.6 tons of slag per year, which is regarded as waste.Environmental impact of slag include copper paralysis, which leads to death due to gastric hemorrhage, if ingested by humans. It may also cause acute dermatitis upon skin exposure. Toxicity may also be uptaken by crops through soil, consequently spreading animals and food sources and increasing the risk of cardiovascular diseases, cancer, cognitive impairment, chronic anemia, and damage to kidneys, bones, nervous system, brain and skin.
Substituting gravel and grit in quarries has been more cost-effective, due to having its sources with better proximity to consumer markets. Trading between countries and establishment of blast furnaces is helping increase slag utilization, hence reducing wastage and pollution.