unit iii. part -a. solid waste engineering and management

7/31/2019 Unit III. Part -A. Solid Waste Engineering and Management

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Unit III

a. Solid waste engineering and management: Types: Hazardous and non-hazardous, characteristicsmanagement of solid waste: collection, reception, transportation, storage, treatment and disposal. 02 Hrs

b. Energy and environmental engineering: Conventional and non-conventional fuels, per capita and global consumption pattern, their environmental impactsalternative energy sources, vehicular emission standards of fuel consumption, green buildings and rating systems. 03 Hrs

What is Solid Waste?Solid wastes may be defined as the organic or inorganic solid substances produced by various activities of thesociety which have lost their value to the first user

Solid wastes are any discarded (abandoned or considered waste-like) materials. Solid wastes can be solid, liquidsemi-solid or containerized gaseous material.(Solid waste means any garbage, refuse, sludge from a wastewater treatment plant, water supply treatment plantor air pollution control facility and other discarded materials including solid, liquid, semi-solid, or containedgaseous material, resulting from industrial, commercial, mining and agricultural operations, and from communityactivities, but does not include solid or dissolved materials in domestic sewage, or solid or dissolved materials inirrigation return flows or industrial discharges that are point sources subject to permit under 33 USC 1342, as

amended (86 Stat. 880), or source, special nuclear or by-product material as defined by the Atomic Energy Act of1954, as amended (68 Stat. 923) except as may be provided by existing agreements between the State of NewYork and the government of the United States (see section 360-1.3 of this Part).A material is discarded if it is abandoned by being:

disposed of (Discharged, deposited, injected, dumped, spilled, leaked or placed into or on any land orwater so that such material or any constituent thereof may enter the environment or be emitted into the airor discharged into groundwater or surface water);

burned or incinerated, including being burned as a fuel for the purpose of recovering usable energy; or

accumulated, stored or physically, chemically or biologically treated (other than burned or incinerated)instead of or before being disposed of.)

Examples of solid wastes:

waste tires

septage

scrap metal

latex paints

furniture and toys

domestic refuse (garbage)

discarded appliances and vehicles

uncontaminated used oil and anti-freeze

empty aerosol cans, paint cans and compressed gas cylinders

construction and demolition debris, asbestos

1. Types of solid wasteSolid waste can be classified into different types depending on their source:

Household waste is generally classified as municipal waste,

Industrial waste as hazardous waste, and

Biomedical waste or hospital waste as infectious waste.

1.1 Non-Hazardous/Municipal solid waste


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Municipal solid waste consists of household waste, construction and demolition debris, sanitation residue,and waste from streets. This garbage is generated mainly from residential and commercial complexes. With risingurbanization and change in lifestyle and food habits, the amount of municipal solid waste has been increasingrapidly and its composition changing. In 1947 cities and towns in India generated an estimated 6 million tonnes ofsolid waste, in 1997 it was about 48 million tonnes. More than 25% of the municipal solid waste is not collected atall; 70% of the Indian cities lack adequate capacity to transport it and there are no sanitary landfills to dispose othe waste. The existing landfills are neither well equipped or well managed and are not lined properly to protectagainst contamination of soil and groundwater.

Over the last few years, the consumer market has grown rapidly leading to products being packed in cansaluminium foils, plastics, and other such nonbiodegradable items that cause incalculable harm to the environmentIn India, some municipal areas have banned the use of plastics and they seem to have achieved success. Forexample, today one will not see a single piece of plastic in the entire district of Ladakh where the local authoritiesimposed a ban on plastics in 1998. Other states should follow the example of this region and ban the use of itemsthat cause harm to the environment. One positive note is that in many large cities, shops have begun packing itemsin reusable or biodegradable bags. Certain biodegradable items can also be composted and reused. In fact properhandling of the biodegradable waste will considerably lessen the burden of solid waste that each city has to tackle.

There are different categories of waste generated, each take their own time to degenerate (as illustrated inthe table below).

The type of litter we generate and the approximate time it takes to

degenerate

Type of litter Approximate time it takes todegenerate the litter

Organic waste such as vegetable andfruit peels, leftover foodstuff, etc.

a week or two.

Paper 1030 days

Cotton cloth 25 months

Wood 1015 years

Woolen items 1 year

Tin, aluminium, and other metal itemssuch as cans

100500 years

Plastic bags one million years?

Glass bottles undetermined

1.2 Hazardous waste

A waste or combination of wastes of a solid, liquid, contained gaseous, or semisolid form which maycause, or contribute to, an increase in mortality or an increase in serious irreversible, or incapacitating reversible

illness, taking into account the toxicity of such waste, its persistence and degradability in nature, its potential foraccumulation or concentration in tissue, and other factors that may otherwise cause or contribute to adverse acuteor chronic effects on the health of persons or other organisms.

Waste exhibiting one or more of the following four characteristics is considered hazardous:

Toxicity.

Corrosivity.

Ignitability.

Reactivity.Toxicity: Waste that exhibits the Toxicity Characteristic (TC) poses a substantial threat to human health and theenvironment. Waste toxicity is measured by using the Toxicity Characteristic Leaching Procedure (TCLP) (40


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CFR 261.24). The TCLP extract is analyzed for lead (or other constituents) to determine if it is above or below theallowable TC regulatory threshold, which for lead is 5 ppm (milligrams/ liter).

Leachable lead analysis differs from total lead analysis, which is typically performed on paint chipsduring a risk assessment or inspection, in that leachable lead is dependent on the type of lead compound presentand the size of the particle (that is, its solubility). Because total lead analysis does not determine the specific leadcompound present, it is difficult, if not impossible, to predict how much of the lead will be leachable. ThereforeXRF or paint-chip analysis (by the usual hot nitric acid digestion/ atomic absorption spectroscopy methods) areunlikely to help determine leachability. The total lead levels determined by a paint-chip analysis are usable in two

circumstances: total lead level that is very low (e.g., less than 100 ppm), indicates that waste should not exceed the

TC regulatory threshold; and

total lead levels can be used in combination with total waste volume estimates to determinewhether recycling for lead recovery is feasible.

Corrosivity: Corrosive waste has a pH that is either less than or equal to 2 (highly acidic) or greater than or equalto 12.5 (highly basic), or which can corrode steel at a certain rate (40 CFR 261.22). Unneutralized caustic paintstrippers and acidic paint strippers (including the resulting sludge) may be corrosive.Ignitability: Ignitable waste generally includes liquids with flash points below 140F (60C), flammable solidsand compressed gases, and oxidizers (40 CFR 261.21). Certain solvents from paint strippers (e.g., xylene) and theresulting sludge or slurry waste may be ignitable.

Reactivity: Lead-based paint hazard control projects are unlikely to produce reactive waste. Reactive wasteincludes substances that are capable of easily generating explosive or toxic gases, especially when mixed withwater (40 CFR 261.23). These also include waste that is unstable and undergoes violent change withoudetonating.1.3 Hospital waste

Hospital waste is generated during the diagnosis, treatment, or immunization of human beings or animalsor in research activities in these fields or in the production or testing of biologicals. It may include wastes likesharps, soiled waste, disposables, anatomical waste, cultures, discarded medicines, chemical wastes, etc. These arein the form of disposable syringes, swabs, bandages, body fluids, human excreta, etc. This waste is highlyinfectious and can be a serious threat to human health if not managed in a scientific and discriminate manner. Ithas been roughly estimated that of the 4 kg of waste generated in a hospital at least 1 kg would be infected.

Surveys carried out by various agencies show that the health care establishments in India are not givingdue attention to their waste management. After the notification of the Bio-medical Waste (Handling andManagement) Rules, 1998, these establishments are slowly streamlining the process of waste segregationcollection, treatment, and disposal. Many of the larger hospitals have either installed the treatment facilities or arein the process of doing so.

Impacts of Solid Wastes:Due to accelerated economic development in recent decades and a rapid urbanization and an uncontrolled

population growth coupled with changes in the consumption patterns of the urban dweller have resulted in anexcessive generation of municipal solid waste (MSW).

To date, landfill is the most commonly employed for MSW disposal worldwide. Landfill can be in the

form of an uncontrolled open dump or of a full containment site engineered to protect the aquatic environment.Unlike engineered landfills, open dumps do not have bottom liners to prevent the seepage of leachate or top coverto retain moisture within the fill. Nor do these traditional landfills have a top cover or other preventive measuresto reduce methane emission into the atmosphere.

Methane and carbondioxide are the principal gases produced from the decomposition of the organicfraction of solid waste in the landfill. Methane gas (CH 4) has a 21-fold global warming potential as compared tocarbon dioxide (CO 2). According to the Intergovernmental Panel on Climate Change, such emissions contributeto 18% of the total methane emissions to the atmosphere, ranging from 9 to 70 Tg (megatonnes) annuallyTherefore, landfills have been implicated as the largest source of atmospheric methane in the world, leading to anatural phenomenon called "global warming" (Hansen, 2005a).


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Due to global warming, changing temperature and rainfall patterns will bring a variety of pressure uponplant and animal life. If temperature rises as projected, one-third of species will be lost from their habitat, eitherby moving elsewhere or by becoming extinct (Hansen, 2005b).

In addition to global warming, open dumps pose a serious threat to the aquatic environment. One of thegreatest environmental concerns associated with MSW landfilling is the generation of leachate. Depending onrainfall conditions, the color of leachate varies from black to brown.

A landfill site may still produce leachate with a high concentration of NH 3-N for over 50 years afterfilling operations have ceased. Unless properly treated, leachate that seeps from a landfill can infiltrate the surface

water, posing potentially serious hazards not only to aquatic organisms, but also to public health in the long-runFor this reason, landfill leachate represents a potentially serious environmental threat with regard to the pollutantsintroduced into the aquatic environment.

Considering the consequence of excessive MSW generation worldwide, an integrated solid managementplan and its implementation needs to be undertaken consistently. The outcomes of the scheme may provide inputsfor local government and relevant stakeholders such as landfill operators to formulate and implement integratedMSW in a holistic manner. These strategies may provide a policy framework to accomplish the target of reducingMSW generation worldwide by 1% annually.

2. Management of solid waste


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Waste management is the collection, transport,processing,recycling or disposal ofwaste materials, usually onesproduced by human activity, in an effort to reduce their effect on human health or local aesthetics or amenity. Afocus in recent decades has been to reduce waste materials' effect on the natural world and the environment and torecoverresources from them.

Waste management practices differ for developed and developing nations, for urban and rural areas, and forresidential, industrial, and commercial producers. Waste management for non-hazardous residential andinstitutional waste in metropolitan areas is usually the responsibility of local government authorities, while

management for non-hazardous commercial and industrial waste is usually the responsibility of the generator.

2.1 Principles of SWM:

Four Rs (Refuse, Reuse, Recycle, Reduce) to be followed for waste management

1. Refuse. Instead of buying new containers from the market, use the ones that are in the house. Refuse to buy new itemthough you may think they are prettier than the ones you already have.

2. Reuse. Do not throw away the soft drink cans or the bottles; cover them with homemade paper or paint on them and usthem as pencil stands or small vases.

3. Recycle. Use shopping bags made of cloth or jute, which can be used over and over again [will this come under recyclor reduce?].Segregate your waste to make sure that it is collected and taken for recycling.

4. Reduce. Reduce the generation of unnecessary waste, e.g. carry your own shopping bag when you go to the market anput all your purchases directly into it.

2.2 Functional Elements of SWM:

The activities associated with the management of Solid Waste can be grouped into six functional groups;

2.2.1- Waste Generation.This step is simply identification step.

2.2.2- Waste handling and separation, storage, and processing at the source.Handling and separation activities until placed in storage containers. From the stand point of materialsspecifications and revenues from the sale of recovered materials, best place to separate for reuse and recycling.
http://en.wikipedia.org/wiki/Transporthttp://en.wikipedia.org/wiki/Waste_treatmenthttp://en.wikipedia.org/wiki/Recyclinghttp://en.wikipedia.org/wiki/Wastehttp://en.wikipedia.org/wiki/Healthhttp://en.wikipedia.org/wiki/Aestheticshttp://en.wikipedia.org/wiki/Natural_worldhttp://en.wikipedia.org/wiki/Natural_environmenthttp://en.wikipedia.org/wiki/Natural_resourcehttp://en.wikipedia.org/wiki/Developed_nationhttp://en.wikipedia.org/wiki/Developing_nationhttp://en.wikipedia.org/wiki/Urban_areahttp://en.wikipedia.org/wiki/Rural_areahttp://en.wikipedia.org/wiki/Residential_areahttp://en.wikipedia.org/wiki/Industryhttp://en.wikipedia.org/wiki/Commercehttp://en.wikipedia.org/wiki/Hazardoushttp://en.wikipedia.org/wiki/Local_governmenthttp://en.wikipedia.org/wiki/Transporthttp://en.wikipedia.org/wiki/Waste_treatmenthttp://en.wikipedia.org/wiki/Recyclinghttp://en.wikipedia.org/wiki/Wastehttp://en.wikipedia.org/wiki/Healthhttp://en.wikipedia.org/wiki/Aestheticshttp://en.wikipedia.org/wiki/Natural_worldhttp://en.wikipedia.org/wiki/Natural_environmenthttp://en.wikipedia.org/wiki/Natural_resourcehttp://en.wikipedia.org/wiki/Developed_nationhttp://en.wikipedia.org/wiki/Developing_nationhttp://en.wikipedia.org/wiki/Urban_areahttp://en.wikipedia.org/wiki/Rural_areahttp://en.wikipedia.org/wiki/Residential_areahttp://en.wikipedia.org/wiki/Industryhttp://en.wikipedia.org/wiki/Commercehttp://en.wikipedia.org/wiki/Hazardoushttp://en.wikipedia.org/wiki/Local_government


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2.2.3- CollectionGathering of the solid waste and recyclables.Waste collection is the component ofwaste management which results in the passage of a waste material fromthe source of production to either the point oftreatment or final disposal. Waste collection also includes thekerbside collection ofrecyclable materials that technically are not waste, as part of a municipal landfill diversionprogram.

2.2.4- Separation and processing and transformation of solid wastes.

Separation and processing usually occurs at materials recovery center (MRF), transfer station, combustionfacilities, disposal sites. Waste transformation is supplied by altering the waste physically, chemically, andbiologically (decreases the amount to be landfilled)

2.2.4.1 Pulverization

1. To reduce to powder or dust, usually by crushing, pounding orgrinding. To break up into tiny particles:bray, crush,granulate, grind, mill, powder, triturate. Seehelp/harm/harmless.

2.2.4.2 Hammer mill

A type of impact mill or crusher in which materials are reduced in size by hammers revolving rapidly in a verticalplane within a steel casing. Also known as beater mill. A grinding machine which pulverizes feed and otherproducts by several rows of thin hammers revolving at high speed.

2.2.4.3 Baling

A technique used to convert loose refuse into heavy blocks by compaction; the blocks are then burned and areburied in sanitary landfill.

2.2.5- Transfer and transport.Proper transport means to be used with trem cards with detailed disclosure.

2.2.6- Disposal
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Waste Disposal Methods

Disposal methods for waste products vary widely, depending on the area and type of waste material. For example,in Australia, the most common method of disposal of solid household waste is in landfill sites, as it is a largecountry with a low-density population. By contrast, in Japan it is more common for waste to be incineratedbecause the country is smaller and land is scarce. Other waste types (such as liquid sewage) will be disposed of indifferent ways in both countries.

2.2.6.1 Landfill

Disposing of waste in a landfill is one of the most traditional method of waste disposal, and it remains a commonpractice in most countries. Historically, landfills were often established in disused quarries, mining voids orborrow pits. A properly-designed and well-managed landfill can be a hygienic and relatively inexpensive methodof disposing of waste materials in a way that minimises their impact on the local environment. Older, poorly-designed or poorly-managed landfills can create a number of adverse environmental impacts such as wind-blownlitter, attraction of vermin, and generation of leachate where result of rain percolating through the waste andreacting with the products of decomposition, chemicals and other materials in the waste to produce the leachatewhich canpollutegroundwaterand surface water. Another byproduct of landfills is landfill gas (mostly composedofmethane and carbon dioxide), which is produced as organic waste breaks down anaerobically. This gas can

create odor problems, kill surface vegetation, and is a greenhouse gas.

Design characteristics of a modern landfill include methods to contain leachate, such as clay or plastic liningmaterial. Disposed waste is normally compacted to increase its density and stablise the new landform, and coveredto prevent attracting vermin (such as mice orrats) and reduce the amount of wind-blown litter. Many landfills alsohave a landfill gas extraction system installed after closure to extract the landfill gas generated by thedecomposing waste materials. Gas is pumped out of the landfill using perforated pipes and flared off or burnt in agas engine to generate electricity. Even flaring the gas is a better environmental outcome than allowing it toescape to the atmosphere, as this consumes the methane, which is a far more potent greenhouse gas than carbondioxide.

Many local authorities, especially in urban areas, have found it difficult to establish new landfills due toopposition from owners of adjacent land. Few people want a landfill in their local neighborhood. As a result, solidwaste disposal in these areas has become more expensive as material must be transported further away fordisposal (or managed by other methods).

This fact, as well as growing concern about the impacts of excessive materials consumption, has given rise toefforts to minimise the amount of waste sent to landfill in many areas. These efforts include taxing or levyingwaste sent to landfill, recycling the materials, converting material to energy, designing products that use lessmaterial, and legislation mandating that manufacturers become responsible for disposal costs of products orpackaging. A related subject is that ofindustrial ecology, where the material flows between industries is studiedThe by-products of one industry may be a useful commodity to another, leading to a reduced materials waste

stream.

Some futurists have speculated that landfills may one day be mined: as some resources become more scarce, theywill become valuable enough that it would be economical to 'mine' them from landfills where these materials werepreviously discarded as valueless. A related idea is the establishment of a 'monofill' landfill containing only onewaste type (e.g. waste vehicle tyres), as a method of long-term storage.

2.2.6.2 Incineration
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management systems, which is proven to be both cost effective and also appears to help in urban povertyalleviation. However, the very high human cost of these activities including disease, injury and reduced lifeexpectancy through contact with toxic or infectious materials would not be tolerated in a developed country.

2.2.6.4. Recycling

Recycling means to recover for other use a material that would otherwise be considered waste. The popularmeaning of recycling in most developed countries has come to refer to the widespread collection and reuse of

various everyday waste materials. They are collected and sorted into common groups, so that the raw materialsfrom these items can be used again (recycled).

In developed countries, the most common consumer items recycled include aluminium beverage cans, steel, foodand aerosol cans, HDPE and PET plastic bottles, glass bottles and jars, paperboard cartons, newspapersmagazines, and cardboard. Other types of plastic (PVC, LDPE, PP, and PS) are also recyclable, although not ascommonly collected. These items are usually composed of a single type of material, making them relatively easyto recycle into new products.

The recycling of obsolete computers and electronic equipment is important, but more costly due to the separationand extraction problems. Much electronic waste is sent to Asia, where recovery of the gold and copper can cause

environmental problems (monitors contain lead and various "heavy metals", such as selenium and cadmium; bothare commonly found in electronic items).

Recycled or used materials have to compete in the marketplace with new materials. The cost of collecting andsorting the materials often means that they are equally or more expensive than virgin materials. This is most oftenthe case in developed countries where industries producing the raw materials are well-established. Practices suchas trash picking can reduce this value further, as choice items are removed (such as aluminium cans). In somecountries, recycling programs are subsidised by deposits paid on beverage containers.

However, most economic systems do not account for the benefits to the environment of recycling these materialscompared with extracting virgin materials. It usually requires significantly less energy, water and other resources

to recycle materials than to produce new materials. For example, recycling 1000 kg of aluminum cans savesapproximately 5000 kg ofbauxite ore being mined (source: ALCOA Australia) and prevents the generation of15.17 tonnes CO2 greenhouse gases; recycling steel saves about 95% of the energy used to refine virgin ore.

2.2.6.5 Composting and anaerobic digestion

Waste materials that are organic in nature, such as plant material, food scraps, and paper products, are increasinglybeing recycled. These materials are put through a composting and/or digestion system to control the biologicaprocess to decompose the organic matter and kill pathogens. The resulting stabilized organic material is thenrecycled as mulch or compost for agricultural or landscaping purposes.

There are a large variety of composting and digestion methods and technologies, varying in complexity fromsimple windrow composting of shredded plant material, to automated enclosed-vessel digestion of mixeddomestic waste. These methods of biological decomposition are differentiated as being aerobic in compostingmethods oranaerobic in digestion methods, although hybrids of the two methods also exist.

Examples

The Green Bin Program, a form of organic recycling used in Toronto and surrounding municipalities, makes useof anaerobic digestion to reduce the amount of garbage shipped to landfills in the United States. This is the newestfacet of a three-stream waste management system has been implemented in the city and is a step towards the goa
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of diverting 70% of current waste. Green Bins allow organic waste to be composted and turned into nutrient richsoil. Examples of accepted waste products for the Green Bin are food products and scraps, soiled papers andsanitary napkins.

Edmonton has adopted large-scale composting to deal with its urban waste. Its composting facility is one of thelargest in the world, representing 35 per cent of Canada's industrial composting capacity. The $100 million co-composter and various recycling programs enable Edmonton to recycle 60% of its residential waste. The co-composter itself is 38,690 square metres in size, equivalent to 8 football fields. It's designed to process 200,000

tonnes of residential solid waste per year and 22,500 dry tonnes of biosolids, turning them into 80,000 tonnes ofcompost annually.

The BIOBIN is an on-site in-vessel organic waste management solution for small industrial and retail organicwaste (primarily food waste and small green waste). The BiobiN is used to collect food waste at shopping centers,schools, hospitality sites, etc, and the bin has a built in aeration and biofiltration system, that blows air through thewaste, initiating the composting process and effectively managing any odor. The end product is then transportedto a larger organics recycling facility for final processing into soil conditioner. The BiobiN reduces the need forfrequent pickups and reduces waste going to landfill.

Uses of biodegradable waste

Biodegradable waste is a little recognised resource. Through correct waste management, often using the two keyprocesses ofanaerobic digestion and composting, it can be converted into valuable products.

Anaerobic digestion converts biodegradable waste into several products, includingbiogas, which can be used togenerate renewable energy orheat for local heating, and soil amendment (digestate). Composting convertsbiodegradable waste into compost.

2.2.6.6 Source Reduction (Waste Prevention)

Source reduction can be a successful method of reducing waste generation. Practices such as grasscycling,

backyard composting, two-sided copying of paper, and transport packaging reduction by industry have yieldedsubstantial benefits through source reduction.

Source reduction has many environmental benefits. It prevents emissions of many greenhouse gases, reducespollutants, saves energy, conserves resources, and reduces the need for new landfills and combustors.

2.2.6.7 Recycling

Recycling, including composting, diverted 79 million tons of material away from disposal in 2005, up from 15million tons in 1980, when the recycle rate was just 10% and 90% of MSW was being combusted with energyrecovery or disposed of by landfilling.

Typical materials that are recycled include batteries, recycled at a rate of 99%, paper and paperboard at 50%, andyard trimmings at 62%. These materials and others may be recycled through curbside programs, drop-off centers,buy-back programs, and deposit systems.

Recycling prevents the emission of many greenhouse gases and water pollutants, saves energy, supplies valuableraw materials to industry, creates jobs, stimulates the development of greener technologies, conserves resourcesfor our children's future, and reduces the need for new landfills and combustors.
http://en.wikipedia.org/wiki/Edmonton%2C_Albertahttp://en.wikipedia.org/wiki/Natural_resourcehttp://en.wikipedia.org/wiki/Waste_managementhttp://en.wikipedia.org/wiki/Anaerobic_digestionhttp://en.wikipedia.org/wiki/Compostinghttp://en.wikipedia.org/wiki/Biogashttp://en.wikipedia.org/wiki/Renewable_energyhttp://en.wikipedia.org/wiki/Heathttp://en.wikipedia.org/wiki/Digestatehttp://en.wikipedia.org/wiki/Composthttp://en.wikipedia.org/wiki/Edmonton%2C_Albertahttp://en.wikipedia.org/wiki/Natural_resourcehttp://en.wikipedia.org/wiki/Waste_managementhttp://en.wikipedia.org/wiki/Anaerobic_digestionhttp://en.wikipedia.org/wiki/Compostinghttp://en.wikipedia.org/wiki/Biogashttp://en.wikipedia.org/wiki/Renewable_energyhttp://en.wikipedia.org/wiki/Heathttp://en.wikipedia.org/wiki/Digestatehttp://en.wikipedia.org/wiki/Compost


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Recycling also helps reduce greenhouse gas emissions that affect global climate. In 1996, recycling of solid wastein the United States prevented the release of 33 million tons of carbon into the air-roughly the amount emittedannually by 25 million cars.

unit iii. part -a. solid waste engineering and management

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