Editing Recycling (section)

== Recycling consumer waste ==

=== Collection ===
[[File:DeutscheBahnRecycling20050814 CopyrightKaihsuTai Rotated.jpg|thumb|upright|A three-sided bin at a railway station in [[Germany]], intended to separate paper ''(left)'' and plastic wrappings ''(right)'' from other waste ''(back)'']]

A number of systems have been implemented to collect recyclates from the general waste stream, occupying different places on the spectrum of trade-off between public convenience and government ease and expense. The three main categories of collection are drop-off centers, buy-back centers and curbside collection.<ref name="gar" /> About two-thirds of the cost of recycling is incurred in the collection phase.<ref>{{Cite journal|last=Waldrop|first=M. Mitchell|date=2020-10-01|title=One bin future: How mixing trash and recycling can work|url=https://www.knowablemagazine.org/article/sustainability/2020/recycle-it-all|journal=Knowable Magazine|doi=10.1146/knowable-092920-3|s2cid=224860591|access-date=12 October 2020|archive-date=18 October 2020|archive-url=https://web.archive.org/web/20201018031423/https://knowablemagazine.org/article/sustainability/2020/recycle-it-all|url-status=live|doi-access=free}}</ref>

==== Curbside collection ====
{{Main|Curbside collection}}
[[File:ACT recycling truck.jpg|thumb|left|A recycling truck collecting the contents of a [[recycling bin]] in [[Canberra]], [[Australia]]]]
[[File:Opróżnianie klatki na odpady z tworzyw sztucznych w 60-tysięcznym Tomaszowie Mazowieckim.jpg|thumb|Emptying of segregated rubbish containers in [[Tomaszów Mazowiecki]], Poland]]

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.

In mixed waste collection, recyclates are collected mixed with the rest of the waste, and the desired materials are sorted out and cleaned at a central sorting facility. This results in a large amount of recyclable waste (especially paper) being too soiled to reprocess, but has advantages as well: The city need not pay for the separate collection of recyclates, no public education is needed, and any changes to the recyclability of certain materials are implemented where sorting occurs.<ref name="gar"/>

In a commingled or [[Single-stream recycling|single-stream system]], [[Recyclable plastic|recyclables]] are mixed but kept separate from non-recyclable waste. This greatly reduces the need for post-collection cleaning, but requires [[public education]] on what materials are recyclable.<ref name="gar" /><ref name="economisttruth"/>

=====Source separation=====
Source separation is the other extreme, where each material is cleaned and sorted prior to collection. It requires the least post-collection sorting and produces the purest recyclates. However, it incurs additional [[operating cost]]s for collecting each material, and requires extensive public education to avoid recyclate [[contamination]].<ref name="gar"/> In [[Oregon]], USA, [[Oregon Department of Environmental Quality|Oregon DEQ]] surveyed multi-family property managers; about half of them reported problems, including contamination of recyclables due to trespassers such as [[homelessness|transients]] gaining access to collection areas.<ref>{{Cite web|url=https://www.oregon.gov/deq/FilterDocs/recmultistate.pdf|title=The State of Multi-Tenant Recycling in Oregon|date=April 2018|access-date=26 May 2019|archive-date=26 May 2019|archive-url=https://web.archive.org/web/20190526212922/https://www.oregon.gov/deq/FilterDocs/recmultistate.pdf|url-status=live}}</ref>

Source separation used to be the preferred method due to the high cost of sorting commingled (mixed waste) collection. However, advances in sorting technology have substantially lowered this overhead, and many areas that had developed source separation programs have switched to what is called ''co-mingled collection''.<ref name="economisttruth"/>

==== Buy-back centers ====
[[File:Automat do przyjmowania butelek zwrotnych w 60-tysięcznym Tomaszowie Mazowieckim Warszawska róg Szerokiej.jpg|thumb|upright|left|[[Reverse vending machine]] in Tomaszów Mazowiecki, Poland]]
At buy-back centers, separated, cleaned recyclates are purchased, providing a clear incentive for use and creating a stable supply. The post-processed material can then be sold. If profitable, this conserves the emission of greenhouse gases; if unprofitable, it increases their emission. Buy-back centres generally need government subsidies to be viable. According to a 1993 report by the U.S. [[National Waste & Recycling Association]], it costs an average $50 to process a ton of material that can be resold for $30.<ref name="gar" />

==== Drop-off centers ====
[[File:Keynsham Recycling Centre, upper deck.jpg|thumb|A drop-off center in the [[United Kingdom]], where they are generally named Recycling Centres]]
Drop-off centers require the waste producer to carry 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.

==== Distributed recycling ====
For some waste materials such as plastic, recent technical devices called [[recyclebot]]s<ref name="RPJ">{{cite journal |last1 = Baechler |first1 = Christian |last2 = DeVuono |first2 = Matthew |last3 = Pearce |first3 = Joshua M. |year = 2013 |title = Distributed Recycling of Waste Polymer into RepRap Feedstock |url = https://www.academia.edu/2643418 |journal = Rapid Prototyping Journal |volume = 19 |issue = 2 |pages = 118–125 |doi = 10.1108/13552541311302978 |s2cid = 15980607 |access-date = 29 December 2017 |archive-date = 2 December 2021 |archive-url = https://web.archive.org/web/20211202111135/https://www.academia.edu/2643418 |url-status = live }}</ref> enable a form of distributed recycling called DRAM ([[distributed recycling additive manufacturing]]). Preliminary [[life-cycle analysis]] (LCA) indicates that such distributed recycling of [[HDPE]] to make filament for [[3D printers]] in rural regions consumes less energy than using virgin resin, or using conventional recycling processes with their associated transportation.<ref name="LCA">{{Cite journal|last1=Kreiger|first1=M.|last2=Anzalone|first2=G. C.|last3=Mulder|first3=M. L.|last4=Glover|first4=A.|last5=Pearce|first5=J. M.|date=2013|title=Distributed Recycling of Post-Consumer Plastic Waste in Rural Areas|url=https://www.cambridge.org/core/journals/mrs-online-proceedings-library-archive/article/abs/distributed-recycling-of-postconsumer-plastic-waste-in-rural-areas/C553E81AD6A084FE7FC30FEEA51CA9AC|journal=MRS Online Proceedings Library |language=en|volume=1492|pages=91–96|doi=10.1557/opl.2013.258|s2cid=18303920|issn=0272-9172|access-date=8 February 2023|archive-date=8 February 2023|archive-url=https://web.archive.org/web/20230208010141/https://www.cambridge.org/core/journals/mrs-online-proceedings-library-archive/article/abs/distributed-recycling-of-postconsumer-plastic-waste-in-rural-areas/C553E81AD6A084FE7FC30FEEA51CA9AC|url-status=live}}</ref><ref>{{cite journal | last1 = Kreiger | first1 = M.A. | author-link4 = J. M. Pearce | last2 = Mulder | first2 = M.L. | last3 = Glover | first3 = A.G. | last4 = Pearce | first4 = J. M. | year = 2014 | title = Life Cycle Analysis of Distributed Recycling of Post-consumer High Density Polyethylene for 3-D Printing Filament | url = https://www.academia.edu/6188555 | journal = Journal of Cleaner Production | volume = 70 | pages = 90–96 | doi = 10.1016/j.jclepro.2014.02.009 | bibcode = 2014JCPro..70...90K | access-date = 5 September 2014 | archive-date = 2 December 2021 | archive-url = https://web.archive.org/web/20211202111134/https://www.academia.edu/6188555 | url-status = live }}</ref>

Another form of distributed recycling mixes waste plastic with sand to make bricks in [[Africa]].<ref>{{Cite AV media |title=Young Inventor Makes Bricks From Plastic Trash |author= ((Insider Business)) | series = World Wide Waste|url=https://www.youtube.com/watch?v=iFcPqXxAUWM |date= 12 October 2021 |access-date=2023-02-26 | via = YouTube}}</ref> Several studies have looked at the properties of recycled waste plastic and sand bricks.<ref>{{Cite journal |last1=Kumar |first1=Rishabh |last2=Kumar |first2=Mohit |last3=Kumar |first3=Inder |last4=Srivastava |first4=Deepa |date=2021 |title=A review on utilization of plastic waste materials in bricks manufacturing process |url=https://linkinghub.elsevier.com/retrieve/pii/S2214785321032570 |journal=Materials Today: Proceedings |language=en |volume=46 |pages=6775–6780 |doi=10.1016/j.matpr.2021.04.337|s2cid=236599187 }}</ref><ref>{{Cite journal |last1=Chauhan |first1=S S |last2=Kumar |first2=Bhushan |last3=Singh |first3=Prem Shankar |last4=Khan |first4=Abuzaid |last5=Goyal |first5=Hritik |last6=Goyal |first6=Shivank |date=2019-11-01 |title=Fabrication and Testing of Plastic Sand Bricks |journal=IOP Conference Series: Materials Science and Engineering |language=en |volume=691 |issue=1 |page=012083 |doi=10.1088/1757-899x/691/1/012083 |bibcode=2019MS&E..691a2083C |s2cid=212846044 |issn=1757-899X|doi-access=free }}</ref> The composite pavers can be sold at 100% profit while employing workers at 1.5× the minimum wage in the West African region, where distributed recycling has the potential to produce 19 million pavement tiles from 28,000 tons of plastic water sachets annually in [[Ghana]], [[Nigeria]], and [[Liberia]].<ref>{{Cite journal |last1=Tsala-Mbala |first1=Celestin |last2=Hayibo |first2=Koami Soulemane |last3=Meyer |first3=Theresa K. |last4=Couao-Zotti |first4=Nadine |last5=Cairns |first5=Paul |last6=Pearce |first6=Joshua M. |date=October 2022 |title=Technical and Economic Viability of Distributed Recycling of Low-Density Polyethylene Water Sachets into Waste Composite Pavement Blocks |journal=Journal of Composites Science |language=en |volume=6 |issue=10 |pages=289 |doi=10.3390/jcs6100289 |issn=2504-477X|doi-access=free }}</ref> This has also been done with COVID19 masks.<ref>{{Cite web |work=CBC |title=Single-use face masks get new life thanks to Regina engineer |url=https://www.cbc.ca/news/canada/saskatchewan/face-mask-repurposing-landscaping-tiles-regina-1.6752754 | last = Samson | first = Sam <!-- yep, well done Sam's parents --> | date= 19 February 2023 }}</ref>

=== Sorting ===
[[File:Recycling Video.webm|thumb|Video of recycling sorting facility and processes]]

Once commingled recyclates are collected and delivered to a [[materials recovery facility]], the materials must be sorted. This is done in a series of stages, many of which involve automated processes, enabling a truckload of material to be fully sorted in less than an hour.<ref name="economisttruth" /> Some plants can now sort materials automatically; this is known as [[single-stream recycling]]. Automatic sorting may be aided by robotics and machine learning.<ref>{{Cite web|url=https://resource-recycling.com/recycling/2019/05/07/how-recycling-robots-have-spread-across-north-america/|title=How recycling robots have spread across North America|date=7 May 2019|website=Resource Recycling News|language=en-US|access-date=29 August 2019|archive-date=8 May 2019|archive-url=https://web.archive.org/web/20190508123102/https://resource-recycling.com/recycling/2019/05/07/how-recycling-robots-have-spread-across-north-america/|url-status=live}}</ref><ref>{{Cite web|url=https://www.therobotreport.com/amp-robotics-announces-largest-deployment-of-ai-guided-recycling-robots/|title=AMP Robotics announces largest deployment of AI-guided recycling robots|date=27 June 2019|website=The Robot Report|language=en-US|access-date=29 August 2019|archive-date=16 July 2019|archive-url=https://web.archive.org/web/20190716111353/https://www.therobotreport.com/amp-robotics-announces-largest-deployment-of-ai-guided-recycling-robots/|url-status=live}}</ref> In plants, a variety of materials is sorted including paper, different types of plastics, glass, metals, food scraps, and most types of [[Batteries (journal)|batteries]].<ref>{{cite web |last = None |first = None |title = Common Recyclable Materials |url = http://www.epa.gov/smm/wastewise/pubs/commonmats.pdf |publisher = United States Environmental Protection Agency |access-date = 2 February 2013 |date = 10 August 2015 |archive-date = 24 April 2013 |archive-url = https://web.archive.org/web/20130424084201/http://www.epa.gov/smm/wastewise/pubs/commonmats.pdf |url-status = live }}</ref> A 30% increase in recycling rates has been seen in areas with these plants.<ref>{{cite web |work=ScienceDaily |date=October 1, 2007 |url=https://www.sciencedaily.com/videos/2007/1002-recycling_without_sorting.htm |title=Recycling Without Sorting: Engineers Create Recycling Plant That Removes The Need To Sort |archive-url=https://web.archive.org/web/20080831095259/https://www.sciencedaily.com/videos/2007/1002-recycling_without_sorting.htm |archive-date=31 August 2008 }}</ref> In the US, there are over 300 materials recovery facilities.<ref>{{Cite web|url=https://resource-recycling.com/recycling/2018/10/01/sortation-by-the-numbers/|title=Sortation by the numbers|date=1 October 2018|website=Resource Recycling News|language=en-US|access-date=29 August 2019|archive-date=29 August 2019|archive-url=https://web.archive.org/web/20190829191919/https://resource-recycling.com/recycling/2018/10/01/sortation-by-the-numbers/|url-status=live}}</ref>

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

[[File:Glass and plastic recycling 065 ubt.JPG|thumb|left|Early sorting of recyclable materials: glass and plastic bottles in [[Poland]].]]

Next, automated machinery such as disk screens and air classifiers separate the recyclates by weight, splitting lighter paper and plastic from heavier glass and metal. Cardboard is removed from mixed paper, and the most common types of plastic—[[Polyethylene terephthalate|PET]] (#1) and [[HDPE]] (#2)—are collected, so these materials can be diverted into the proper collection channels. This is usually done by hand; but in some sorting centers, [[Spectroscopy|spectroscopic]] scanners are used to differentiate between types of paper and plastic based on their absorbed wavelengths.<ref name="economisttruth" /> Plastics tend to be incompatible with each other due to differences in [[chemical composition]]; their [[polymer]] molecules repel each other, similar to oil and water.<ref>{{cite book |last1=Goodship |first1=Vannessa |title=Introduction to Plastics Recycling |date=2007 |publisher=iSmithers Rapra Publishing |isbn=978-1-84735-078-7 }}{{page needed|date=April 2021}}</ref>

Strong magnets are used to separate out [[ferrous metal]]s such as iron, steel and [[tin can]]s. [[Non-ferrous metal]]s are ejected by magnetic [[eddy current]]s: A rotating magnetic field [[electromagnetic induction|induces]] an electric current around aluminum cans, creating an eddy current inside the cans that is repulsed by a large [[magnetic field]], ejecting the cans from the stream.<ref name="economisttruth" />

[[File:Recycling Point - geograph.org.uk - 1382457.jpg|thumb|A recycling point in [[New Byth]], Scotland, with separate containers for paper, plastics, and differently colored glass]]

Finally, glass is sorted according to its color: brown, amber, green, or clear. It may be sorted either by hand,<ref name="economisttruth" /> or by a machine that uses colored filters to detect colors. Glass fragments smaller than {{convert|10|mm|in}} cannot be sorted automatically, and are mixed together as "glass fines".<ref>{{cite web |last = None |first = None |title = What Happens to My Recycling? |url = http://www.1coast.com.au/page8390/What-happens-to-my-recycling.aspx |publisher = 1coast.com.au |access-date = 21 July 2014 |url-status = dead |archive-url = https://web.archive.org/web/20140811010701/http://www.1coast.com.au/page8390/What-happens-to-my-recycling.aspx |archive-date = 11 August 2014 }}</ref>

In 2003, [[San Francisco]]'s Department of the Environment set a citywide goal of zero waste by 2020.<ref>{{cite web |title = Best Recycling Programs in the US & Around the World |url = http://www.cpmfg.com/2012/04/11/the-best-recycling-programs-in-the-us-around-the-world-infographic/ |publisher = cmfg.com |access-date = 1 February 2013 |archive-date = 12 May 2015 |archive-url = https://web.archive.org/web/20150512093851/http://www.cpmfg.com/2012/04/11/the-best-recycling-programs-in-the-us-around-the-world-infographic/ |url-status = dead }}</ref> San Francisco's refuse hauler, [[Recology]], operates an effective recyclables sorting facility that has helped the city reach a record-breaking landfill diversion rate of 80% as of 2021.<ref>{{cite web |url = http://www.sfenvironment.org/news/press-release/mayor-lee-announces-san-francisco-reaches-80-percent-landfill-waste-diversion-leads-all-cities-in-north-america |title = Mayor Lee Announces San Francisco Reaches 80 Percent Landfill Waste Diversion, Leads All Cities in North America |publisher = San Francisco Department of the Environment |date = 5 October 2012 |access-date = 9 June 2014 |archive-date = 24 June 2014 |archive-url = https://web.archive.org/web/20140624003706/http://www.sfenvironment.org/news/press-release/mayor-lee-announces-san-francisco-reaches-80-percent-landfill-waste-diversion-leads-all-cities-in-north-america |url-status = live }}</ref> Other American cities, including Los Angeles, have [https://www.ecowatch.com/best-cities-for-recycling-2652630134.html achieved similar rates].