Municipal recycling facilities, Montgomery County, MD

Single-stream (also known as “fully commingled” or "single-sort")

recycling Recycling is the process of converting waste materials into new materials and objects. The recovery of energy from waste materials is often included in this concept. The recyclability of a material depends on its ability to reacquire the p ...

refers to a system in which all

paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distrib ...

fibers, plastics, metals, and other containers are mixed in a collection truck, instead of being sorted by the depositor into separate commodities (

newspaper A newspaper is a Periodical literature, periodical publication containing written News, information about current events and is often typed in black ink with a white or gray background. Newspapers can cover a wide variety of fields such as p ...

, paperboard, corrugated fiberboard,

plastic Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...

glass Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling ( quenching ...

, etc.) and handled separately throughout the collection process. In single-stream, both the collection and processing systems are designed to handle this fully commingled mixture of recyclables, with materials being separated for reuse at a

materials recovery facility A materials recovery facility, materials reclamation facility, materials recycling facility or Multi re-use facility (MRF, pronounced "murf") is a specialized plant that receives, separates and prepares recyclable materials for marketing to end-u ...

. The single-stream option replaces the dual-stream option, which is where people separate certain recyclable materials and place them in separate containers for collection. From an end consumer perspective, single-stream is easier to participate in. However, single-stream recycling has disadvantages, including the output of lower quality plastics and paper to recyclers. This lower quality material has to be processed more downstream. The increased flow of decreased quality recyclables from Europe and North America in part due to single-stream recycling was part of China's motivation for launching its

Operation National Sword The Operation National Sword was a policy initiative launched in 2017 by the Government of China to monitor and more stringently review recyclable waste imports. Before the policy, China was importing the vast majority of recyclables from North Amer ...

policy.

Advantages

Materials Recovery Facility April 2015 11

Proponents of single-stream recycling note several advantages: * Reduced sorting effort by residents may mean that more recyclables are moved to the curb and more residents may participate in recycling; * Reduced collection costs because single-compartment trucks are cheaper to purchase and operate, collection can be automated, and collection routes can be serviced more efficiently. Single-stream reduced the amount of time it takes for a driver to collect the recyclables, which reduces the driver time on the road. * Greater fleet flexibility, which allows single-compartment vehicles to be used to collect recycling, providing greater fleet flexibility and reducing the number of reserve vehicles needed. To avoid confusing customers, a large sign or banner is sometimes used to distinguish when a

refuse truck A garbage truck is a truck specially designed to collect municipal solid waste and transport it to a solid waste treatment facility, such as a landfill, recycling center or transfer station. In Australia they are commonly called rubbish truc ...

is being used to collect recycling (instead of refuse). * Worker injuries may decrease because the switch to single-stream is often accompanied by a switch from bins to cart-based collection. * Changing to single-stream may provide an opportunity to update the collection and processing system and to add new materials to the list of recyclables accepted; and * More paper grades may be collected, including junk mail,

telephone book A telephone directory, commonly called a telephone book, telephone address book, phonebook, or the white and yellow pages, is a listing of telephone subscribers in a geographical area or subscribers to services provided by the organization that ...

s and mixed residential paper.

Disadvantages

Potential disadvantages of single-stream recycling may include: * Initial

capital cost Capital costs are fixed, one-time expenses incurred on the purchase of land, buildings, construction, and equipment used in the production of goods or in the rendering of services. In other words, it is the total cost needed to bring a projec ...

for: ** New carts ** Different collection vehicles ** Upgrading the processing facility * Processing costs may increase compared to multiple-stream systems. Overall, single-stream costs about $3 more per ton than dual-stream. * Increase of contamination in the recycling container. Possible reduced commodity prices due to contamination of paper or plastic * Increased

downcycling Downcycling, or cascading, is the recycling of waste where the recycled material is of lower quality and functionality than the original material. Often, this is due to the accumulation of tramp elements in secondary metals, which may exclude the ...

of paper, i.e., use of high quality fibers for low-end uses like boxboard because of presence of contaminants; * Possible increase in residual rates after processing (chiefly because of increased breakage of

) * Potential for diminished public confidence if more recyclables are destined for landfill disposal because of contamination or inability to market materials.

Single-stream system

A single-stream system is a complex network of machinery that uses a combination of newer and older technologies to sort materials for recycling, including PET, HDPE, aluminum, tin cans, cardboard and paper. List of equipment used in a single-stream system: # Back Scraping Drum: spreads materials out on a conveyor belt # OCC Screen: sorts cardboard/ old corrugated containers (OCC). Cardboard is sent to the Single Ram Baler to be baled. # Fines Screen: all material except for cardboard go through Fines Screen. Fines Screen sorts out pieces of glass and fine materials less than two inches long. Glass is sent to the Glass Cleanup System for more separating. # News Screen: sorts out newspaper from the rest of the recycling. # Elliptical Separator: sorts 2D objects from 3D objects. # Ferrous Magnet: pulls all ferrous metals to the magnet such as tin cans and steel. # Optical Sorter: reads the containers for PET plastic. # Eddy Current Separator: pulls out all of the aluminum and non-ferrous materials. # Two-Ram Baler: bales everything except for the cardboard and clear film. # Glass Cleanup System: cleans glass coming off fines screen by pulling off all the light fractions. # Closed Door Baler: bales the clear film plastic. # Motion Floor: walking floor bunkers that stores corrugated and mixed paper. # Single Ram Baler: bales all corrugated materials.

By country

United States

Phoenix, Arizona, began exploring single-stream recycling in 1989. A contract was awarded to CRCInc in 1992, and its MRF, the first large-scale recycling facility to process commingled materials in North America, began operation in 1993. Subsequently, many large and small municipalities across the United States began single-stream programs. As of 2012, there are 248 MRFs operating in the US. As of 2013, 100 million Americans were served by single-stream programs.

References

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External links

How It Works: Inside The Machine That Separates Your Recyclables
��'' Popular Science'' (August 28, 2013)
Single-Stream Recycling Is Easier for Consumers, but Is It Better?
��''

The Atlantic ''The Atlantic'' is an American magazine and multi-platform publisher. It features articles in the fields of politics, foreign affairs, business and the economy, culture and the arts, technology, and science. It was founded in 1857 in Boston, ...

'' (September 19, 2014) Recycling