presentation: waste recycling

7/28/2019 Presentation: Waste Recycling

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Orlando Branco

The advantages ofwaste recycling


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Orlando Branco

Introduction

Recycling is the collection, separation, clean-up and processing of waste material toproduce a marketable material or product;

Recycling can take place within themanufacturing process, eg. Paper industry;

Recycling can take place at the post-consumerstage;

Recycling employs about one million peopleworldwide and is responsible for capitalinvestment totalling around 7 billion.


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Orlando Branco

Aims To demonstrate the types of waste

recycling systems; To explain the types of waste recycling;

To analyse and compare recycled and

virgin material life cycles; To compare energy consumption and

emissions of recycled paper with virgin

paper production; To compare energy emissions savings of

recycling with virgin production;

To examine three successful case studies.


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Orlando Branco

Types of recycling systems

Bring system involves the segregation ofrecyclable materials from household wasteby the public and delivery to a collection

site, eg. Bottle and paper banks; Collect system involves house-to-house

kerbside collection of recyclable materials;

Centralised materials recycling facility The household waste is brought to acentral plant for reclamation and recycling.


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Recycling systems

Bring system has the advantage of beinglow in capital costs, easily accessible andcan provide an easy method of

segregating clean readily marketablematerials;

Collect system provides convenience for

the householder and as a result higherrecovery rates of recyclable materials. Forexample, glass collection rates can be upto 71% and paper 67%;


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Orlando Branco

Recycling systems

Centralised materials recycling facilitiessegregate material streams and processbetween three and eight components ofparticular materials which may beseparated or mixed;

Such facilities handle clean waste andconsequently contamination levels are low

and recovery rates are high. For example,general commercial office waste maycontain levels of paper over 80% byweight.


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Types of waste recycling

Recycling paper can reduce water use by almost60%;

Recycling can reduce energy consumption by40%;

Recycling can decrease air pollution by 74% andwater pollution by 35%;

For countries without significant domesticsources of pulpwood, the main advantage of

recycling paper is to reduce the need forimported pulp. For example, recycled materialcurrently provides a high proportion of fibre usedto make paper and board in Netherlands 69%,Denmark 66%, Spain 55% and UK 53%.

Paper


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Glass recycling reduces the requirement

for raw materials (each tonne of cullet

saves 1.2 tonnes of raw materials such as

sand, soda ash and limestone);

Cullet (waste glass) is cheaper than the

equivalent amount of raw materials and

also saves energy in glass manufacturesince recycled glass melts at a lower

temperature than the raw material;

Glass


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Increasing the amount of cullet can resultin a 15% saving in energy. When usingraw materials, 15% of the weight of input

is lost as waste gases out, while usingcullet, there are no gases. Water used inthis process is reduced by up to 50%;

Up to 80% of glass cullet can beaccepted into the glass making and thereis no limit to the number of times thatglass can be recycled.

Glass


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Pos-industrial plastic waste is well established

and economically viable, since such material is

normally single polymer and is clean, therefore

the reprocessing is a straightforward operation; Recycled plastics can be used either to replace

virgin polymers or can be reprocessed as mixed

plastics to produce wood substitute materials;

Recycled plastics can be used in cases whichaesthetics are unimportant. For example, pipes

or ducting can be made from polyethylene or

PVC and are likely to be buried or hidden.

Plastics


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Making iron and steel from suitable scrap

metal saves about 75% of energy,enormous amounts of left over mine spoil

and huge quantities of water used to make

the steel;

Recycling one tonne of steel saves 900 kg

of raw material;

Metals


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Aluminium can be recycled almost 100%. Thissaves more than 90% of energy costs. It alsosaves tropical rainforests areas where most of

this resource comes from. The forest is clearedand a highly red mud is left behind after miningbauxite (the ore which aluminium is made);

Aluminium can be continuously recycled since

there is no loss of quality during the recycling orre-melting process;

The recycling rates for aluminium are high. Forexample, drink cans 41%, building and

construction 85%, and automotive industry 95%.

Metals


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Textiles that cannot be reused can be recycled.Some fibres wool, cotton and acrylic can be

respun to make new textiles for coats andblankets;

Other textiles are recycled into products likeroofing felt, wiping cloths and stuffing for

upholstery; The use of recycled fibres can save energy in

the region of 50% compared with the use ofvirgin fibre.

Textiles


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Scrap tyres are used by the crumbing sector.For example, after removal of the steel wire the

remaining material is granulated and then usedin brake linings, car bumpers, carpet backingand underlay, sports and playground surfaces;

The retreading of tyres is another way of

recycling. One of the largest users of remouldedtyres is the aircraft industry that remoundsaircraft tyres two or three times;

Approximately 24% of all scrap tyres are now

remoulded.

Tyres


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Recycled x virgin material

Life cycle

Figure 1 Life-cycle assesment for recycled and virgin materials (Williams, 2005)


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Recycled x virgin material

Energy consumption and emissions

Table 1 Recycled and virgin paper Energy consumption and emissions (Williams, 2005)


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Recycled x virgin materialEnergy and emissions savings

Table 2 Energy and emissions of recycling and virgin production (Williams, 2005)


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Case Study 1 - Denmark Aarhus in Denmark has a population of 282,000

people; The overall recycling rates achieves 64%;

Garden waste recycling rates: ~100%;

Industrial and commercial waste recycling rates:56%;

Construction and demolition waste recycling rates:93%;

Collection system: based on a network of streetcontainers (1container x 430 people);

Civic amenity sites where householders candispose of waste.


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Case Study 2 - Germany

Wiesbaden in Germany has a population

of 267,000 people;

Of the 91,000 tonnes of waste produced

each year, 43,500 tonnes are recycled;

Waste recycling rates: 48%;

Recycling scheme: based on collection, anetwork of containers at recycling points

and recycling centres.


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Case Study 3 - UK

Project Integra in the county of Hampshire;

Total population: 1.6 million;

Around 850,000 tonnes per year of wastegenerated;

Recycling rate: 24%;

Recycling scheme: Kerbside collection

(90% coverage of households), theremaining is recycled through wasterecycling centres.


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Conclusions Commercial recycling schemes save vast

amounts of waste from industrial enterprises; Reduce the amount of land required for

landfilling thereby reducing the risk of pollution;

Save energy in comparison with production fromvirgin raw materials. Saving energy helps toreduce all the problems associated with energygeneration: acid rain, smog, radioactive pollutionfrom nuclear accidents, flooding of valleys for

huge hydro-electric power schemes; Minimise pollution and reduce environmental

damage caused by extraction (e.g. mining) andsupply of raw materials;


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Conclusions

Conserve resources and raw materials. This hastwo benefits in that many raw material reservesare finite and the extraction of such resourcescan be destructive to the environment;

Potential energy savings from using scrapmaterials instead of virgin ones: Glass 22%,paper 70%, aluminium 96%, steel 74% andpolyethylene 97%;

Glass, plastic and metals can be melted andreshaped. Paper can be pulped and made intonew paper. Organic waste can be composted.Textiles can be unwoven and into new cloth.


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References Finch, S., 1992. Dont through it all away! Friends of the

Earths guide to waste reduction and recycling. London :Earth Trust.

Parker, S., 1997. Waste, recycling and re-use. Suffolk :Wayland.

Reidy, R., 1996. Solid waste recycling Municipal solidwaste recycling in western Europe to 1996. Oxford :Elsevier.

Smosarski, G., 1995. Material recycling Turning wasteinto valuable raw materials Financial Times

management reports. London : Pearson. Waite, R., 1995. Household waste recycling. London :

Earthscan.

Williams, P.T., 2005. Waste treatment and disposal. 2nded. Chichester : Wiley.

presentation: waste recycling

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